Supplements come AFTER diet, sleep, and exercise - not instead of them. These address deficiencies lifestyle can't fix. Start with 3, not 15.
Prepared by the What Is Brain Fog editorial desk. Clinically reviewed by Dr. Alexandru-Theodor Amarfei, M.D.
Last updated: • Editorial policy • Citation policy
No supplement stack replaces a proper diagnosis. If you haven't completed the core foundations of sleep, diet, movement, and rule-outs, go back. Supplements build on a foundation of addressed mechanisms and clear measurement - they don't substitute for that work. If nothing improves after 30 days of structured lifestyle change, escalate to a full medical workup rather than adding more pills.
You do NOT need 15 supplements. If budget is tight, these 3 cover the most ground:
5g daily, no loading needed. Your brain uses 20% of your energy - creatine is the ATP buffer. 2024 meta-analysis confirmed cognitive benefits. Vegetarians see the largest gains.
Sleep-and-tension overlap tool. Only form shown to cross the blood-brain barrier and increase brain magnesium levels.
Neurotransmitter synthesis. Methylated forms bypass MTHFR variants that affect ~40% of people.
Add one at a time, 2 weeks apart, so you know what's working. Check drug interactions before starting anything new. Add everything else only if these don't improve symptoms after approximately 8 weeks (per standard clinical guidance).
Rough generic estimates, not product endorsements. No financial relationships with supplement brands. Not a formally studied protocol.
The same supplement can have very different evidence depending on the underlying cause of your brain fog. Select your cause below to see which supplements have cause-specific evidence, then visit your cause page for dosing details, safety notes, and the full clinical picture.
A = StrongB = ModerateC = PreliminaryD = Emerging? = Not yet graded
80 supplements
Zinc is most defensible when diet quality is poor, restriction is heavy, or deficiency is plausible. It isn't a universal “testosterone booster,” and it shouldn't distract from sleep apnea, obesity, or proper morning hormone testing.
Better framing: useful when deficiency is on the table, not as a shortcut around diagnosis.
These fit when the pattern includes real deficiency risk, brittle sleep, low sun exposure, muscle tension, or poor intake. They may support the overlap picture, but they don't substitute for confirming low testosterone on two morning draws. When taking D3 above 2,000 IU, consider adding K2 (MK-7, 100-200 mcg) to support calcium metabolism.
Use when: the story has a deficiency signal, not just vague fatigue.
If the real issue is confirmed hypogonadism, untreated sleep apnea, medication effects, or significant obesity-linked suppression, supplements won't correct the main bottleneck. Use them after the evaluation is getting clearer, not instead of it.
Keep the hierarchy straight: diagnosis, reversible-cause treatment, then adjuncts.
Thyroid Context
Thyroid-pattern brain fog is mainly a testing, diagnosis, medication-timing, and overlap problem. Supplements fit here only when a real deficiency, autoimmune overlap, or intake gap is part of the story. They don't replace thyroid labs, levothyroxine timing, or endocrinology follow-up.
Most relevant when Hashimoto's is confirmed or selenium intake is plausibly low. Evidence is mixed: selenium may lower TPO antibodies in some patients, but symptom improvement isn't reliably dramatic.
Typical dose: 200mcg selenomethionine daily if supplementing.
Food note: Brazil nuts aren't a standardized dose. Selenium content varies widely by origin.
Wichman J et al. Thyroid. 2016 (PMID: 27702392); Winther KH et al. Nat Rev Endocrinol. 2020 (PMID: 32001830)
This is the main thyroid-specific combo missing from most supplement pages. It's most relevant in autoimmune thyroiditis or subclinical hypothyroid patterns, where small trials suggest it may improve TSH and antibody-related markers in selected patients.
Typical study pattern: myo-inositol 600mg plus selenium 83mcg daily.
Keep the framing honest: promising for selected Hashimoto's-type cases, not a universal replacement for levothyroxine or endocrine follow-up.
Nordio M et al. Eur Rev Med Pharmacol Sci. 2017 (PMID: 28293260); Nordio M, Basciani S. Int J Endocrinol. 2017 (PMID: 28724185)
Fits best when a measured 25-OH vitamin D deficiency overlaps the thyroid story, especially with autoimmune context, low mood, or diffuse fatigue.
Best next step: check 25-OH vitamin D before treating it like the root cause.
Mazokopakis EE et al. Hell J Nucl Med. 2015 (PMID: 26637501)
Iron belongs here when ferritin is low. It matters for thyroid peroxidase activity and can easily mimic or amplify thyroid-style fatigue and cognitive slowing.
Best next step: check ferritin or the TSH + B12 + ferritin panel.
Hess SY. Thyroid. 2010 (PMID: 20172476)
Mercury Context
Mercury support only makes sense after the exposure story is credible and the testing conversation has started. Supplements here are adjuncts to exposure reduction, not a substitute for lowering mercury intake or getting toxicology advice when levels are truly high.
Selenium fits here because mercury binds selenoproteins and can raise oxidative-stress vulnerability. The most honest framing is protective support, not detox magic.
Typical dose: 200mcg selenomethionine daily if supplementing.
Evidence: Moderate. Strong mechanistic rationale and observational support, but no mercury-specific human RCT proving cognitive improvement from selenium alone.
Ralston NV, Raymond LJ. Toxicology. 2010 (DOI: 10.1016/j.tox.2010.06.004)
Chlorella is often discussed as a binder-style support, but the evidence is mostly mechanistic or animal-based. It belongs in the “maybe helpful, not proven” bucket.
Typical dose: 3-5g daily.
Keep the framing honest: reasonable only after exposure reduction is underway. It should avoid replace testing or give a false sense that active exposure is solved.
NAC makes sense here as glutathione support, not as a proven mercury-clearing therapy. It may fit when oxidative stress and chemical sensitivity overlap the story.
Typical dose: 600-1200mg daily.
Caution: discuss with your clinician first if you take nitroglycerin, anticoagulants, or have a bleeding disorder.
Most relevant when the Long COVID / ME/CFS story looks like poor cellular energy recycling: crashes after small effort, poor bounce-back, and a broader post-viral mitochondrial pattern. It belongs after pacing, not instead of pacing.
Typical dose: 200-400mg/day, usually with food.
Creatine makes the most sense here when the post-viral pattern includes cognitive slowing, heavy effort cost, or poor physical recovery. It supports ATP buffering, but it doesn't fix PEM if pacing is still being ignored.
Typical dose: 3-5g/day.
Better framed as a low-energy stress-reactivity support tool than as a core Long COVID treatment. It may fit when the body feels stuck in a high-alert state, but the evidence is indirect and not specific to PEM recovery.
Typical dose: 600mg/day.
L-theanine fits best as a smoothing tool for wired-but-fragile days, not as proof that you found the root cause. It may reduce jagged high-alert states without strong sedation, but it is still an adjunct with thin condition-specific evidence.
Typical dose: 200mg/day.
Cortisol Context
This isn't a “fix your cortisol with pills” section. These supplements fit best after you have checked sleep debt, caffeine load, alcohol, overtraining, gut overlap, and the actual stressor. They're adjuncts for a stress-pattern story, not proof of endocrine disease.
Strongest direct signal
These are the only entries here with reasonably direct human evidence for either lowering cortisol itself or blunting the endocrine response to acute stress. Even here, the trials are small and this is still adjunct territory.
The cleanest cortisol-specific adjunct here. A small placebo-controlled trial found about a 27.9% reduction in serum cortisol over 60 days, but that doesn't make it a substitute for changing the stressor, fixing sleep, or ruling out true endocrine pathology.
Typical dose: 300-600mg/day.
Evidence: Chandrasekhar K et al. Indian J Psychol Med. 2012 (PMID: 23439798)
One of the more credible “stress response” supplements here. Small trials suggest it can blunt the endocrine response to mental or exercise stress, which makes it more defensible for high-alert evenings than for general brain-fog marketing.
Typical dose: 400-800mg/day.
Evidence: Hellhammer J et al. Stress. 2004 (PMID: 15512856)
Adjuncts and overlap support
The papers below are real, but they support stress smoothing, stress-fatigue, sleep overlap, inflammation overlap, or gut-brain overlap. They don't prove these supplements lower cortisol in a clean, disease-level way.
Better framed as help for stress-related fatigue and under-recovery than as a well-supported cortisol-lowering supplement. It fits the “drained but still switched on” pattern more than a diagnosed hormone disorder.
Typical dose: 200-600mg each morning.
Evidence: Olsson EM et al. Planta Med. 2009 (PMID: 19016404, stress-related fatigue trial)
Best for smoothing the jagged “wired” edge of a stress-pattern day. The evidence is better for acute stress-response support than for treating a true cortisol disorder, so it belongs in the overlap bucket rather than the core endocrine bucket.
Typical dose: 200-400mg/day.
Evidence: Kimura K et al. Biol Psychol. 2007 (PMID: 16930802)
Helpful for: stress-spiked, anxiety-heavy days where the goal is to smooth the edge rather than to prove you found the root diagnosis.
These make more sense when inflammation, gut symptoms, or general stress resilience are part of the picture. They aren't strong “direct cortisol lowering” supplements. Omega-3 has better support for stress-linked inflammation and anxiety buffering, while probiotic evidence is more convincing for gut-brain overlap and subjective stress than for a clean cortisol effect.
Evidence: Kiecolt-Glaser JK et al. Brain Behav Immun. 2011 (PMID: 21784145); Zhang N et al. Brain Behav Immun. 2020 (PMID: 32662591, no significant cortisol effect in that meta-analysis)
Protocol Part 8 Context
These aren't first-line fixes for every hormonal complaint. They belong after testing, sleep, and diet context are clearer, and several of them make sense only with clinician oversight. The hormonal page mentions them because readers keep asking where they fit.
Fits best when the hormonal picture overlaps with high stress tone, brittle sleep, or a “tired but wired” pattern. It isn't a substitute for thyroid testing or endocrine diagnosis.
Typical dose: 300-600mg/day.
Best framed as a daytime stress-fatigue adjunct when the body feels under-recovered, not as proof of “adrenal fatigue.” More useful for strain and fatigue than for primary hormone deficiency.
Typical dose: 200-400mg each morning.
Most relevant when the hormonal pattern includes high-alert evenings, poor shutdown, and a stress-reactivity story. It's an adjunct for nervous-system regulation, not a direct fix for thyroid or sex-hormone disorders.
Typical dose: around 100mg in the evening, adjusted cautiously.
Most defensible when the hormonal story includes insulin resistance, PCOS, cycle irregularity, or metabolic dysfunction. It belongs in the insulin-and-ovary branch of the protocol, not as a universal nootropic.
Typical dose: 2-4g/day, often in a 40:1 myo- to d-chiro-inositol ratio.
Pregnenolone is hormone-adjacent and shouldn't be treated like a casual wellness supplement. It may show up in hormonal-brain-fog conversations, but it carries a much higher threshold for supervision than magnesium, creatine, or omega-3.
Typical dose discussed clinically: 10-50mg/day, only with professional supervision.
Systematic review for 2023 international PCOS guidelines: significant decreases in fasting insulin and HOMA-IR. Comparable to metformin with fewer GI side effects. PCOS brain fog is primarily driven by insulin resistance reducing brain glucose uptake - inositol addresses this directly.
CAUTION: Can cause hypoglycemia (brain fog, shakiness) in women who are NOT insulin resistant. Test HOMA-IR first. 4g myo + 100mg DCI daily. PMID 38163998.
Meta-analysis of 9 RCTs: comparable to metformin for insulin resistance. May be MORE effective for dyslipidemia and lowering androgens. Dual pathway: insulin sensitization + gut microbiome improvement (gut-brain axis). Do NOT combine at full dose with metformin without medical supervision.
500mg TID with meals. Works well alongside inositol per RCT data (PMID 35251851). Watch for hypoglycemia with combination. PMID 30538756.
RCTs show significant anti-androgen effects: testosterone -15%, DHEA -18%. Elevated androgens impair reaction time and word recognition via receptors in the prefrontal cortex. Spearmint addresses this pathway without affecting insulin - complementary to inositol/berberine for dual-pathway coverage. Very popular in r/PCOS. Generally well-tolerated in studied populations.
Anti-androgen RCT: PMID 19585478. Also on the page: chromium picolinate (PMID 26663540), CoQ10 (9 RCTs, PMID 35941510), NAC (18 studies, PMID 39861414).
Berberine + metformin at full doses is HIGH RISK for hypoglycemia. Inositol + metformin: moderate risk, can combine but monitor glucose. The supplement that helps IR-PCOS can WORSEN non-IR-PCOS brain fog (hypoglycemia). Get HOMA-IR tested before starting any insulin sensitizer.
Test first: PCOS is a diagnosis of exclusion. If you haven't tested fasting insulin, androgens, and ruled out thyroid disease, supplements won't clarify the picture.
Up to 80% of people with AUD have thiamine deficiency (Cochrane review, PMID 23818100). Cochrane review: 200mg/day significantly outperformed 5mg/day on cognitive tests. Benfotiamine (600mg/day) has 5x better bioavailability and reduced psychiatric distress in an RCT of 85 alcohol-dependent men (PMID 25908323). Thiamine prevents Wernicke-Korsakoff syndrome - permanent brain damage.
Start immediately. 100-300mg thiamine OR 600mg benfotiamine daily. Cochrane: PMID 23818100. Benfotiamine: PMID 25908323.
Double-blind placebo-controlled study in 55 abstinent alcoholics (PMID 2201652): 2g/day for 90 days significantly improved long-term memory, logical memory, and abstract reasoning. ALCAR crosses the blood-brain barrier, delivers acetyl groups for acetylcholine synthesis, and restores mitochondrial energy production damaged by alcohol.
The strongest direct evidence for alcohol cognitive recovery. Safe in liver disease. PMID 2201652.
Pilot RCT: significant reduction in drinking days. Replenishes glutathione (depleted by alcohol metabolism) and modulates glutamate excitotoxicity during withdrawal. Phase III trial currently underway for cognition and liver markers. Safe alongside naltrexone and acamprosate. Hepatoprotective - one of the few supplements that actively helps the liver.
Also on the alcohol page: B-complex (80% folate deficiency), magnesium (30-50% depletion), phosphatidylcholine (liver repair), omega-3.
If you have active liver disease: AVOID vitamin A (hepatotoxic), sustained-release niacin (hepatotoxic), iron supplements unless tested (accumulates in damaged liver), kava (documented liver failure cases). SAFE: thiamine, B-complex (niacinamide not niacin), magnesium, NAC, ALCAR, phosphatidylcholine, omega-3. L-glutamine: avoid if hepatic encephalopathy (ammonia buildup).
Medication note: Milk thistle may affect naltrexone metabolism (CYP2B6). Disulfiram is contraindicated with any liver disease. Some herbal extracts contain alcohol solvents.
The best-supported lupus supplement. Examine rates it Grade A for lupus, with symptom reduction up to 50% in some trials and consistently above 30%. Interesting finding: lower doses (as low as 160mg EPA + 140mg DHA) outperformed higher doses in some studies.
Typical dose: Start low (300-1000mg EPA+DHA). Higher isn't necessarily better for lupus. Arriens et al. 2015 RCT used 4.5g/day with significant ESR reduction (PMID 26512876).
Helpful for: overall disease activity, inflammation (ESR), possibly fatigue. No known interaction with hydroxychloroquine or prednisone.
One of the few supplements tested specifically in lupus patients with positive results. An RCT of 80 SLE patients (PMID 36810107) found 1800mg/day for 3 months significantly reduced disease activity scores (SLEDAI and BILAG). Works by replenishing glutathione and blocking mTOR overactivation in lupus T cells. A larger Phase 2 trial (210 patients) is ongoing at HSS.
Typical dose: 1800mg/day (600mg three times daily). PMID 36810107.
Helpful for: disease activity, oxidative stress, glutathione depletion. Safe alongside hydroxychloroquine and prednisone.
Lupus patients are commonly deficient due to photosensitivity-driven sun avoidance. A meta-analysis of 3,177 patients across 10 RCTs found supplementation slightly improved lupus symptoms. An earlier meta-analysis of 5 RCTs showed it may improve fatigue but doesn't significantly reduce disease activity on its own. This is deficiency correction, not treatment.
Typical dose: Test 25(OH)D first. Target 40-60 ng/mL. Usually 2000-4000 IU/day. Avoid supplements with added calcium if taking hydroxychloroquine.
Helpful for: confirmed deficiency, fatigue, bone health (especially if on prednisone). PMID 31331447.
Lupus is an overactive immune system. Supplements that stimulate immunity can trigger flares. Avoid: echinacea (immune stimulant, linked to lupus flares), alfalfa (L-canavanine triggers inflammation), spirulina (immune stimulant), and be cautious with melatonin (may worsen lupus in some patients). High-dose vitamin E may also worsen Th2-driven autoimmunity.
Also consider: Curcumin (bioavailable form, 1000mg/day) has an RCT in 70 SLE patients showing reduced anti-dsDNA and IL-6 (PMID 39546036), but Examine rates it Grade C for lupus due to limited evidence beyond proteinuria.
Environment first, often. No supplement protocol can overcome active mold exposure. Find the moisture source, remediate or leave, THEN start support. Most evidence below is Grade C (mechanistic rationale + practitioner protocol consensus, not standalone RCTs). The one exception is cholestyramine (prescription binder) which has placebo-controlled crossover data.
Binders capture mycotoxins in the gut and prevent reabsorption. Cholestyramine (prescription) has the strongest evidence - two double-blind crossover studies showed symptom scores dropping from 22.8 to 3.9. Activated charcoal is the OTC alternative but binds non-specifically and may reduce nutrient absorption.
Critical timing: Take 2+ hours away from ALL medications, food, and other supplements. Some practitioners start fish oil 1 week before binders to reduce intensification reactions.
Mycotoxins deplete glutathione by suppressing the enzymes that make it (Nrf2 pathway). Liposomal glutathione provides the end product directly; NAC feeds the production pathway. They work synergistically. Evidence is mechanistic (PMID 24517907), not from human RCTs - but the biochemical rationale is strong and both are standard in practitioner protocols.
Testing note: Stop both 1 week before mycotoxin urine testing - they can create false negatives.
The Shoemaker CIRS Protocol uses omega-3 at 2400mg EPA + 1800mg DHA daily - much higher than the standard 1-2g dose. This targets MMP-9 and VEGF, key inflammatory markers in mold illness. EPA reduces MMP-9; DHA supports brain cell membrane repair after mycotoxin damage. The protocol dose hasn't been tested independently of the full protocol.
Quality matters: Fish oil is one of the most commonly contaminated supplements. Choose third-party tested brands, especially when your system is already under toxic load.
Most mold supplement evidence is Grade C: strong biochemical rationale and practitioner consensus, but no large human RCTs testing individual supplements for mold-exposed patients. The Shoemaker Protocol has been validated as a complete system (10 clinical studies), but individual components haven't been isolated. If someone tells you a supplement "detoxes mold," ask for the specific human trial - it probably doesn't exist yet.
The best-supported intervention: Remove the exposure. Everything else is support after that step.
Dose matters: 200mg showed inconsistent results; 500mg showed clear benefits. Double-blind placebo-controlled trial (PMID 25603363) found 500mg/day for 12 weeks significantly improved fatigue and depression in MS patients. A second RCT (PMID 30815035) confirmed reduced oxidative stress and improved disability scores in interferon-beta-treated patients.
Why it works in MS: Demyelinated neurons require dramatically more energy to conduct signals. CoQ10 restores mitochondrial ATP production in these energy-starved neurons. PMID 25603363, 30815035.
Phase 2 RCT across 10 US sites: 1200mg/day preserved deep gray matter volume vs trending decrease in placebo group. Crosses the blood-brain barrier. Requires kidney monitoring at this dose.
Caveat: Brain volume was preserved but cognitive test scores did not significantly improve. Neuroprotective but not yet proven as a cognitive enhancer. PMID 41397213.
Exploratory FDG-PET study in 24 MS patients showed IV NAC significantly increased cerebral glucose metabolism. Patients report: "clearer thinking, better short memory, improved executive functioning" starting within days.
Critical interaction: NAC may antagonize dimethyl fumarate (Tecfidera). If you are on Tecfidera, discuss with your neurologist before starting NAC. PMID PMC7033492.
MS is an overactive immune system attacking myelin. Avoid: echinacea, astragalus, cat's claw, elderberry, ginseng, goldenseal, high-dose zinc. Failed supplements: High-dose biotin (MD1003) failed Phase 3 of 642 patients (PMID 33222767). Ginkgo biloba showed no cognitive benefit in Class I RCT (PMID 22955125).
Also on the MS page: Lion's mane (NGF/myelin support, PMID 18844328), vitamin D (disease modifier, not cognitive treatment).
Cordero et al. RCT (PMID 23458405): 300mg/day for 40 days reduced fibromyalgia pain by >50%, significantly improved fatigue, morning tiredness, and tender points (p<0.01). Extended studies up to 3 months confirmed sustained benefit. Also reduces anxiety and depression scores.
Why it works in fibro: Fibromyalgia involves measurable mitochondrial dysfunction. Fibro patients have lower CoQ10 levels than controls. PMID 23458405.
Multicenter study of 257 patients across 53 clinics: 61% energy increase, 30% mental clarity improvement, 29% sleep improvement. Open-label design limits confidence, but consistency across two studies is notable. Works synergistically with CoQ10 - both target mitochondrial energy from different angles.
Pilot study: 66% of 41 patients experienced significant improvement. PMID 17109576.
RCT: significantly reduced stress and pain severity in moderate-severity fibromyalgia patients (p=0.029). Magnesium blocks NMDA receptors involved in central sensitization - the core mechanism of fibromyalgia pain amplification. Low levels increase pain sensitivity, muscle cramping, and sleep disruption.
Form matters: Glycinate for pain/sleep (better GI tolerance). L-threonate for cognitive symptoms (crosses BBB). PMID 35631229.
Most fibromyalgia patients are on duloxetine (Cymbalta), amitriptyline, milnacipran (Savella), or other serotonergic medications. Adding 5-HTP to these can cause serotonin syndrome - a potentially life-threatening condition. Despite 5-HTP appearing on many fibromyalgia supplement lists, it is dangerous for most of the target audience.
Also on the fibro page: Melatonin (low-dose for sleep), EPA-focused omega-3, vitamin D (if deficient).
Gold-standard detoxification trial (PMID 24913818): 291 participants, broccoli sprout beverage increased excretion of benzene conjugates by 61% and acrolein by 23% over 12 weeks. The most potent natural inducer of Phase II detoxification enzymes (glutathione S-transferase) via Nrf2 pathway.
Dose: 30-60mg sulforaphane/day. Makes your body measurably better at clearing toxicants. PMID 24913818.
Organophosphates directly deplete neuronal CoQ10 by 43-72% and cause mitochondrial complex II+III dysfunction. Supplementation restored CoQ10 and increased complex activity by 25-35%. Gulf War illness veterans (OP-exposed) showed significant improvement with CoQ10 in VA-funded RCT. Phase III replication recruiting 200 veterans.
Not generic antioxidant support: Organophosphates specifically poison the CoQ10-dependent electron transport chain. This is replacing what was destroyed. PMID 32306167.
RCT in 30 acute OP poisoning patients: NAC 600mg TID reduced atropine requirements, decreased oxidative stress markers (MDA), and increased glutathione. For chronic exposure: replenishes the glutathione that pesticide metabolism depletes. But if you're still eating pesticide-laden food, this is bailing water from a leaking boat.
Reduce exposure first. Switching to organic for the Dirty Dozen reduces urinary pesticide metabolites by 60% in one week. PMID 26786042.
During acute pesticide poisoning, these supplements are NOT a substitute for emergency medical care. Call 911/Poison Control. Standard treatment is atropine + pralidoxime. Supplements are for chronic low-level exposure alongside exposure reduction.
Also on the pesticides page: ALA (BBB-crossing antioxidant), B-complex (OPIDN protection), curcumin (Nrf2 activation), magnesium, vitamin C, vitamin E.
Meta-analysis of 5 RCTs (n=1,213): significantly superior to placebo for GAD. Head-to-head: 160mg Silexan was SUPERIOR to paroxetine 20mg. As effective as lorazepam 0.5mg. The critical advantage: unlike benzodiazepines, Silexan does NOT impair cognition, cause sedation, or create dependence.
Only the capsule form works. Aromatherapy lavender isn't equivalent. 80mg/day standard; 160mg/day severe anxiety. PMID 36717399.
The overwhelmingly most-recommended starting point in anxiety communities. RCT: 200mg/day improved verbal fluency and executive function. The combination of 200mg L-theanine + 100mg caffeine produces "calm focus" - reducing anxiety enough to free up cognitive bandwidth without sedation.
Safe as SSRI adjunct. RCT showed benefit when added to sertraline. PMID 31623400, 37084960.
Meta-analysis of 12 RCTs (n=1,002): significantly reduced anxiety and stress. Separate RCT: 27.9% serum cortisol reduction. Cognition RCT: improved executive function, memory, and processing speed. Chronic cortisol directly impairs hippocampal memory - ashwagandha addresses this root cause.
Caution: Case report of serotonin syndrome with escitalopram. Discuss with prescriber if on SSRIs. PMID 23439798, 34858513.
If you are on SSRIs, SNRIs, or buspirone, do NOT take 5-HTP, L-tryptophan, or St. John's Wort. Serotonin syndrome is life-threatening. Oral GABA supplements don't cross the blood-brain barrier per the American Academy of Neurology - save your money. Kava increases sedation with sedatives - avoid.
Also on the anxiety page: Magnesium (glycinate + L-threonate), phosphatidylserine (cortisol blunting), EPA-dominant omega-3.
WFSBP/CANMAT 2022 guidelines recommend as adjunctive. Meta-analysis: EPA-pure formulations showed antidepressant effects; DHA-pure did NOT. The formulation matters more than total dose. EPA specifically reduces the neuroinflammation that drives both depression and brain fog.
Dose: 1000-2000mg EPA/day. Must be >=60% EPA to show benefit. Safe with all antidepressants. PMID 31383846.
Landmark RCT: creatine + escitalopram showed dramatically faster improvement than escitalopram alone (Cohen's d = 1.13). Brain imaging confirms creatine increases cerebral phosphocreatine - directly replenishing the depleted energy reserves that make depression feel like "running on empty." The single most discussed supplement for depression fog in patient communities.
Safe with all standard antidepressants. Avoid in bipolar disorder (mania risk). Inexpensive. PMID 22864465.
Meta-analysis of 12 RCTs: large effect size (SMD -1.10), with some studies showing comparable efficacy to standard antidepressants for specific symptoms with a different side-effect profile. Stanford breakthrough: depressed patients have measurably lower ALCAR levels, and the deficit is LARGER in treatment-resistant depression and childhood trauma history. This may be a correctable metabolic factor in some patients, not just a supplement.
Crosses the blood-brain barrier (unlike regular L-carnitine). Particularly effective in elderly. Safe with all antidepressants. PMID 29076953, 30061399.
NEVER combine St. John's Wort with SSRIs, SNRIs, MAOIs, or tricyclics. It causes serotonin syndrome AND reduces antidepressant blood levels via CYP450 induction - the most dangerous supplement-drug interaction in psychiatry. 5-HTP is also contraindicated with serotonergic medications. SAMe can trigger mania in bipolar patients.
Also on the depression page: L-methylfolate 15mg (SSRI adjunct, especially for MTHFR), zinc 25mg (NMDA/BDNF), saffron 30mg (comparable to SSRIs in RCTs), vitamin D.
When brain fog is worse standing and better lying down, the problem is usually blood delivery to the brain - not a supplement deficiency. Lifestyle interventions (salt loading, fluids, compression garments, counter-maneuvers, exercise reconditioning) are far more impactful than any supplement. The items below support perfusion when lifestyle measures are already in place.
Dose: 3,000-5,000mg sodium/day from all sources. The HRS expert consensus recommends 10-12g salt/day for POTS with suspected hypovolemia (PMID 25980576). Evidence: C+ - guideline cornerstone with strong physiological rationale but limited RCT support. The only POTS RCT (n=14) showed hemodynamic improvement without symptom improvement.
Forms: Electrolyte drinks (Vitassium, NormaLyte, LMNT), buffered salt capsules, or dietary salt. Plain salt tablets often cause GI distress. Pair with 2-3L fluid/day.
Contraindicated in heart failure, uncontrolled hypertension, and kidney disease. Monitor blood pressure regularly.
Dose: Ferrous bisglycinate 25-50mg every other day with vitamin C. Alternate-day dosing is 35% more effective than daily (PMID 29032957). Evidence: B+ - a 2025 meta-analysis found significant cognitive improvement (d=0.46) in non-anemic iron-deficient populations (PMID 40945632).
Iron deficiency reduces oxygen-carrying capacity AND impairs compensatory cerebral blood flow - a double hit in someone with already-compromised perfusion. Only works if you are actually iron-deficient. Benefits were absent in non-deficient participants.
Do NOT supplement without a ferritin blood test. Excess iron is toxic. Hemochromatosis affects ~1 in 200 Northern Europeans.
Dose: 200-400mg/day, glycinate or bisglycinate form. Taurate if palpitations are prominent. Evidence: C - no RCTs in POTS. Rationale is deficiency correction (~50% of US adults are deficient) and that fludrocortisone depletes magnesium.
Also on the hypoperfusion cause page: Ginkgo Biloba (mild vasodilator, moderate evidence in existing cognitive impairment only - Cochrane 2026). See the cause page for the full supplement stack with evidence grades.
Nootropics and cognitive enhancers don't help if the problem is blood delivery, not brain chemistry. Knee-high compression stockings are basically useless - blood pools in the abdomen, not just legs. You need waist-high compression (30-40mmHg) or abdominal binders.
Standing desks make hypoperfusion worse. Seated with legs elevated is better. The lifestyle interventions (salt, fluids, compression, counter-maneuvers) matter far more than any supplement for this cause.
Most keto brain fog is electrolyte deficiency. Keto causes renal sodium wasting, which pulls potassium and water with it. The resulting electrolyte deficit causes headache, fatigue, brain fog, and muscle cramps - the cluster people call "keto flu."
Evidence: B - strong physiological rationale, consistent community reports. Skartun et al. 2025, Bostock et al. 2020
Safety: If you have kidney disease or take potassium-sparing diuretics, check with your doctor before supplementing potassium.
MCTs bypass normal fat digestion and go directly to the liver for ketone production, potentially speeding the transition into nutritional ketosis and reducing adaptation symptoms. C8 (caprylic acid) is the most efficiently converted to beta-hydroxybutyrate.
Evidence: C - narrative review evidence; MCTs increase BHB dose-dependently but few trials tested fog reduction specifically. Harvey et al. 2018
Safety: Start low - MCT oil can cause GI distress (cramping, diarrhea) if introduced too quickly. Build up over 1-2 weeks.
Context: Keto brain fog is one of the few causes where supplements ARE the primary intervention, not an adjunct. Electrolyte supplementation is the treatment. See the full keto cause page for timeline, mechanism, and when to consider that keto may not be right for you.
No supplement can replicate the cognitive benefits of physical activity. Exercise increases cerebral blood flow, triggers BDNF release, improves glucose regulation, and reduces inflammation. A 20-minute daily walk produces measurable cognitive improvement that no pill matches.
What the evidence says: Multiple meta-analyses confirm exercise outperforms supplements, brain-training apps, and most pharmacological interventions for cognitive enhancement in healthy adults.
If bloodwork reveals deficiencies in iron, vitamin D, or B12 - common in sedentary individuals - correction through supplementation is standard medical care, not a brain fog supplement strategy. These deficiencies can also cause fatigue that prevents exercise, creating a cycle.
Key tests: Ferritin (target >50 ng/mL), vitamin D 25-OH (target 40-60 ng/mL), B12. Ask your doctor if fatigue is preventing you from exercising.
The best-supported PMDD supplement. A 497-woman RCT (Thys-Jacobs 1998) showed 48% symptom reduction. This is closer to "medical intervention" than typical supplement - take it consistently throughout the cycle, not just during symptoms.
Typical dose: 1200mg daily, split as 600mg twice daily.
Helpful for: overall PMDD symptom burden including mood, physical symptoms, and cognitive complaints.
The combination may help with PMDD symptoms (De Souza 2000). Magnesium glycinate is often better tolerated than oxide. B6 supports serotonin synthesis, which is disrupted in PMDD during the luteal phase.
Typical dose: 200mg magnesium + 50mg B6 daily.
Helpful for: as adjunct to calcium; may help with anxiety, tension, sleep quality during luteal phase.
Not a supplement, but more important than most supplements. 30 minutes of moderate cardio 4-5x/week during the luteal phase may help more than adding a fifth pill to a stack (Ravichandran et al. 2022, PMID 35996479). Exercise increases serotonin and BDNF.
Evidence: Ravichandran et al. 2022 (PMID 35996479) - may reduce PMS/PMDD symptoms.
If you experience suicidal ideation during the luteal phase, this is a recognized PMDD symptom requiring immediate clinical attention - not just more supplements. Luteal-phase SSRIs work within days for PMDD (unlike weeks for depression).
Crisis line: 988 Suicide and Crisis Lifeline (call or text 988).
Sleep Supplements
Supplements can support sleep, but only if you match the supplement to the actual problem. Timing issues need timing tools. Quality issues need different tools. Obstruction needs neither.
These shift when you fall asleep, not how deeply you sleep.
These may support relaxation or deeper sleep architecture.
Useful when the sleep problem is secondary to another cause.
Quick Decision Guide
Most useful when the problem is circadian timing rather than airway collapse: delayed sleep window, shift-work drift, jet-lag-style timing mismatch, or a late second wind. Start low. Bigger doses aren't automatically better.
Use when: you are sleepy at the wrong time, not when you are snoring, gasping, or waking unrefreshed despite enough hours in bed.
Better framed as a support tool for people who are deficiency-prone, cramp-prone, restless at night, or carrying a light, brittle sleep pattern. It isn't a universal brain-fog fix.
Use when: sleep feels wired, restless, or physically tense. Check the deficiency story first instead of treating it like a generic stack item.
Glycine has some support for light, fractured sleep, but the evidence is still thin. Treat it like a small experiment, not a foundational intervention.
Use when: you are troubleshooting sleep quality after the bigger levers are already in place.
No supplement fixes a collapsing airway. If the real pattern is sleep apnea, the main tools are testing, CPAP, oral appliances, positional therapy, weight-linked treatment, or procedure-based options.
Adjunct only: supplements may help overlap issues like deficiency or circadian drift, but they don't treat the apnea itself.
Common Misconception
Melatonin is a timing signal, not a sleeping pill. It helps shift when you fall asleep, not how deeply. Using it wrong leads to disappointment or side effects.
When melatonin actually helps
When melatonin won't help
Key Facts
If your problem is timing (can't fall asleep until 2 AM, jet lag, irregular schedule), melatonin may help. If your problem is anxiety, apnea, pain, or middle-of-night waking, melatonin is the wrong tool.
ADHD Supplements
ADHD supplement marketing is loud. The evidence is quieter. Supplements may help at the margins, but they are not a substitute for proper evaluation or first-line treatment.
These have some research backing, usually modest effect size.
Worth checking if there's reason to suspect deficiency.
Popular but lacking evidence or potentially problematic.
Key Points
This is still the best-supported ADHD supplement, but the effect is modest and most of the evidence comes from youth populations. Use it as an adjunct, not a substitute for diagnosis, structure, sleep repair, or medication when medication is clearly indicated.
Helpful for: people who want a low-risk adjunct after the basic work is already in place.
Endometriosis note: An RCT in young women with confirmed endometriosis (SAGE trial, Nodler et al. 2020, PMID: 32453393) found no significant pain reduction from omega-3 at 6 months. General anti-inflammatory support evidence is moderate, but don't expect endo-specific benefit. See the Endometriosis Brain Fog page.
Melatonin belongs here because delayed sleep timing is common in ADHD. It isn't an all-purpose “brain fog supplement.” It makes the most sense when the ADHD pattern is being amplified by a late sleep phase.
Helpful for: a delayed sleep window, not for daytime attention on its own.
Iron belongs here when ferritin is low. Magnesium fits better when brittle sleep, muscle tension, or obvious dietary gaps are part of the story. Zinc is the weakest of the three and makes the most sense when intake is poor or deficiency is actually on the table. None of them are generic ADHD stack items.
Helpful for: confirmed low ferritin, likely magnesium deficiency, or documented zinc gaps, not for bypassing real workup.
If the real issue is untreated sleep apnea, thyroid disease, depression, bipolar II, or medication side effects, an ADHD supplement stack won't solve the core problem. Use supplements after the evaluation is getting clearer, not instead of it.
Helpful reminder: a calmer day on a supplement doesn't prove you found the diagnosis.
No supplements are specifically studied for autistic burnout - the primary treatment is demand reduction, sensory management, and masking reduction. However, autistic adults have higher rates of restricted eating (ARFID co-occurs in 12-33%) and nutritional gaps that can compound brain fog. Screen and supplement confirmed deficiencies rather than taking generic stacks.
Meta-analysis found significantly lower vitamin D levels in autistic populations compared to controls. Deficiency is common due to sensory-driven indoor preference, restricted diets, and sun avoidance. Supplement only after confirming deficiency via 25-OH vitamin D test. Typical dose: 1000-4000 IU/day depending on levels.
Why it matters in autism: Vitamin D affects neuroinflammation and immune regulation. Deficiency compounds cognitive fog from any cause. PMID 27904735.
Small studies suggest magnesium + vitamin B6 may improve behavioral symptoms in some autistic individuals. Evidence is preliminary (Grade C). Magnesium is commonly low in restricted diets. Typical dose: 200-400mg magnesium with 25-50mg B6. Glycinate or threonate forms are generally better tolerated.
Why it may help in autism: Magnesium supports GABA function and nervous system regulation. B6 is a cofactor for neurotransmitter synthesis. Both are commonly depleted in restricted diets. PMID 16846100.
If you are quitting caffeine entirely, supplements usually aren't needed - withdrawal resolves on its own within 1-2 weeks. These are relevant only for people moderating caffeine use or managing withdrawal symptoms.
Most defensible as a caffeine companion. L-theanine reduces jitteriness and crash while preserving the cognitive benefits of moderate caffeine. Not a withdrawal supplement - this is for people who want to keep some caffeine but improve the experience. Found naturally in green tea (~25mg per cup) or available as a supplement.
Typical dose: 100-200mg taken with caffeine. A 2025 meta-analysis of 50 RCTs confirmed L-theanine plus caffeine improved cognition and mood vs caffeine alone (Payne et al., PMID 40314930). A 2019 RCT found 200mg/day reduced stress symptoms (Hidese et al., PMID 31623400).
Marginally useful during caffeine withdrawal for headache relief. Caffeine increases urinary magnesium excretion, so replenishment during withdrawal has physiological rationale. General evidence supports magnesium for headache management, though not specific to caffeine withdrawal.
Typical dose: 200-400mg magnesium glycinate or citrate. Well-tolerated. Already covered in the Sleep and general supplement sections for other indications.
If nutrient deficiency is your best lead, don't start with a blind stack. Start with the workup, then move from the cause page into the exact tool you need next.
Iron belongs here when ferritin is actually low or the blood-loss story is strong. It isn't a generic “energy supplement.” Use it to correct documented depletion, not to guess at every fatigue problem.
Helpful for: low ferritin, iron deficiency without anemia, heavy menstrual blood loss, pregnancy (iron requirements nearly double), postpartum depletion, or proven low iron stores.
Practical note: alternate-day dosing is often easier to absorb and tolerate than brute-force daily dosing.
Pregnancy note: Iron is especially critical during pregnancy when requirements nearly double. Many pregnant women need additional iron beyond their prenatal vitamin. Target ferritin >30 ng/mL (optimal >50). Discuss dosing with your OB provider. See the Pregnancy Brain Fog page for full context.
Endometriosis note: Heavy menstrual bleeding from endometriosis is one of the most common causes of iron depletion in reproductive-age women. Ferritin can be falsely normal during active inflammation - request full iron studies (serum iron, TIBC, transferrin saturation) alongside ferritin. Iron bisglycinate 25-50mg is often better tolerated than ferrous sulfate. See the Endometriosis Brain Fog page for full context.
B12 and folate belong here when the story includes restrictive eating, gut disease, acid suppression, metformin, neuropathy, or borderline labs that still fit the pattern. They're correction tools, not enhancement tools.
Helpful for: confirmed B12 or folate deficiency, borderline B12 with elevated MMA or homocysteine, or pernicious-anemia or malabsorption patterns.
Vitamin D makes the most sense when a measured deficiency is present. Magnesium fits better when intake is poor, sleep is brittle, muscle tension is part of the story, or vitamin D repletion keeps stalling.
Helpful for: documented vitamin D deficiency, low magnesium intake, or plausible low-reserve overlap rather than a random stack experiment. In trauma populations, magnesium may support nervous system regulation and sleep, and vitamin D deficiency is common when avoidance behaviour limits outdoor activity.
K2 note: When supplementing vitamin D at 2,000+ IU daily, consider adding vitamin K2 (MK-7, 100-200 mcg) to support calcium metabolism. K2 directs calcium to bones rather than arteries. Not essential but prudent at higher doses.
Pregnancy note: Vitamin D deficiency is common in pregnancy and associated with adverse outcomes. ACOG supports screening at-risk women. Dose during pregnancy: 1,000-4,000 IU daily depending on levels, as directed by your OB provider. See the Pregnancy Brain Fog page for full context.
Nutrient repletion is strongest when it follows testing, pattern recognition, and a plan to find the cause of the deficiency. It's weakest when it turns into five supplements and no explanation for why the levels got low.
Helpful reminder: iron overload is real, folate can obscure B12 issues, and even useful supplements still need follow-up labs.
Omega-3 is one of the more defensible adjuncts when depression, inflammatory load, or diet quality are part of the picture, but it's still an adjunct. It doesn't replace diagnostic work, therapy, or medication review for bipolar disorder, PTSD, OCD, psychosis, or severe anxiety.
Evidence context: the support is modest and condition-specific. This is closer to “worth considering” than “core treatment,” especially outside depressive patterns.
Evidence note: psychiatry omega-3 evidence is commonly cited from Sarris et al. 2012 and later adjunctive trials, not from a brain-fog-specific stack study.
NAC is sometimes used as an adjunct in psychiatric care, especially when compulsive loops, oxidative stress framing, or heavy overlap with inflammation is part of the discussion. It isn't a stand-alone fix for cognitive impairment and shouldn't distract from the main diagnosis.
Best framing: a lower-certainty support tool that may deserve discussion, not a substitute for trauma therapy, mood stabilization, or antipsychotic review.
Evidence note: psychiatric NAC evidence is mixed and emerging; Berk et al. 2013 is often cited in bipolar-spectrum adjunct discussions.
If the fog is happening in the context of bipolar disorder, PTSD, OCD, psychosis, or severe anxiety, the first supplement question is often the wrong question. A medication timeline, sleep review, and substance review usually matter more than adding magnesium number six.
Practical rule: if the regimen is sedating or cognitively costly, review that before assuming you need a nootropic stack.
The supplement question on the meds page is usually: what has the medication quietly depleted? PPIs, metformin, and some anticonvulsants can make B12, magnesium, iron, folate, or vitamin D worth checking before you assume the fog is psychological or permanent.
Best framing: targeted repletion after testing, plus a medication review to decide whether the regimen itself should change.
Hallucinations, mania, severe dissociation, suicidality, and sudden loss of reality-testing aren't supplement problems. Those states need urgent psychiatric or emergency care, not a stack experiment.
Use adjuncts only after safety and diagnosis are in motion.
Kidney-related fog isn't a “stack” problem first. Start with the kidney story itself: eGFR trend, urine albumin, anemia, bicarbonate, blood pressure, and diabetes control. Supplements only make sense after that workup is getting clearer.
Vitamin D fits kidney care when deficiency is documented and the renal team is already interpreting calcium, phosphorus, and parathyroid status. In CKD this isn't generic “wellness vitamin D” logic; the stage of kidney disease changes what form and dose make sense.
Best use: measured deficiency or CKD-mineral-bone context, with clinician oversight rather than self-escalating doses.
This is one of the kidney examples where the “supplement” is really part of medical management. It can help when metabolic acidosis is part of the CKD story, but it also adds sodium and can worsen edema or blood pressure if used casually.
Best use: only when your nephrologist is tracking serum bicarbonate and using it as part of a kidney-protection plan.
Iron matters here when CKD-related anemia, low ferritin, or low transferrin saturation is part of the fog picture. In advanced CKD, the more relevant question is often oral versus IV iron, not whether it is often recommended to freestyle an iron stack from the internet.
Best use: documented CKD-anemia or iron deficiency with ferritin and TSAT follow-up, usually alongside the broader kidney workup.
Kidney disease changes how the body handles minerals, vitamins, herbs, and “detox” products. Supplements that look harmless on a general wellness page can accumulate, raise potassium or phosphorus, interact with transplant or blood-pressure medications, or simply distract from the real treatment conversation.
Practical rule: if the fog seems kidney-linked, ask the nephrology team before adding anything beyond a clearly documented deficiency correction.
Typically, check with your pharmacist or doctor before adding supplements to your medication regimen. Full interaction database →
Air-quality fog is one of the clearest examples where the main intervention is environmental, not supplemental. If the fog tracks with a room, a building, smoke, traffic, gas cooking, or poor bedroom ventilation, fix the air first.
If particles, wildfire smoke, traffic, or dust are the trigger, a HEPA filter does more for the actual mechanism than another anti-inflammatory capsule. It treats the air you are breathing instead of asking your body to work around the exposure.
Best use: bedroom, office, or nursery where the trigger clearly follows the room.
Broccoli sprouts, omega-3, or other oxidative-stress supports can be reasonable adjuncts, but they aren't substitutes for ventilation, combustion control, or a cleaner bedroom. If the fog clearly follows the environment, treat the environment as the primary intervention.
Practical rule: if opening the room changes the fog faster than any pill, stay focused on the room.
Vitamin C enhances non-heme iron absorption significantly.
Dose: 200-500mg vitamin C taken with iron supplement
Hallberg L et al., Hum Nutr Appl Nutr 1986;40(2):97-113. PMID 3700141
Dose: 2,000-5,000 IU daily to reach 40-60 ng/mL
Evidence: Grade A - landmark RCT. The VITAL trial (n=25,871, median 5.3 years follow-up) found vitamin D 2,000 IU/day reduced autoimmune disease incidence by 22% over 5 years, with stronger effects after 2+ years of supplementation.
Hahn et al., BMJ 2022 (PMID 35082139) - VITAL trial
Dose: 1,000-3,000 mg/day combined EPA+DHA
Evidence: Grade B - umbrella review of 21 systematic reviews shows consistent benefit for RA and SLE specifically, with anti-inflammatory effects via EPA-derived resolvins. Higher EPA ratios may matter more than total dose.
Hong et al., Autoimmun Rev 2024 (PMID 39357585); Hahn et al., BMJ 2022 (PMID 35082139)
Dose: 500-1000mg daily with piperine or lipid formulation for absorption. Discuss with your prescriber if on immunosuppressants.
Evidence: Grade B - systematic review and meta-analysis of 31 RCTs across 10 autoimmune diseases found clinically significant reductions in inflammatory markers (CRP, IL-6) and disease activity scores. Bioavailability is the limiting factor - standard curcumin absorbs poorly without piperine or lipid formulation.
Yang et al., Front Immunol 2022 (PMID 35979355) - 31 RCTs, 10 autoimmune diseases
Dose: Multi-strain probiotic containing Lactobacillus and Bifidobacterium species daily. Specific strains matter - L. casei has the strongest RA evidence.
Evidence: Grade B - meta-analysis of 80 RCTs across 14 autoimmune diseases found probiotics improved symptoms and inflammatory markers. Effects were strongest with multi-strain formulas containing Lactobacillus and Bifidobacterium, taken for 8+ weeks.
Zeng et al., BMC Med 2024 (PMID 38475833) - 80 RCTs, 14 autoimmune diseases
Dose: 200mcg selenomethionine daily. Do not exceed 400mcg/day. Particularly important if Hashimoto's thyroiditis is part of your autoimmune picture.
Evidence: Grade B for Hashimoto's specifically - meta-analysis of 21 RCTs (n=1,600): selenium reduced TPOAb at 3, 6, and 12 months. Effect was most consistent with 200mcg selenomethionine. For RA, a separate RCT showed reduced joint tenderness and swelling.
Hashimoto's meta-analysis: PMC 10951571 (21 RCTs, n=1,600); RA RCT: PMID 37477848
Dose: 600mg twice daily. Can be subtly energizing - avoid evening dosing if it affects sleep.
Evidence: Grade B for SLE - RCT in 80 SLE patients (1800mg/day, 3 months) significantly reduced disease activity scores. NAC replenishes glutathione and blocks mTOR-driven T cell dysfunction in lupus, addressing a known immunological pathway.
SLE RCT: Jafari-Nakhjavani et al., Trials 2023 (PMID 36810107); SLE mTOR: Lai et al., Arthritis Rheum 2012 (PMID 22549432)
Diet and exercise changes first. Berberine has metabolic evidence in type 2 diabetes populations, but it is a supplement, not a replacement for lifestyle or prescribed therapy. Discuss it with your doctor before adding it if you take other medications.
Dose: 500mg 2-3x daily with meals
Evidence: Moderate - Yin et al., Metabolism, 2008: pilot RCT in type 2 diabetes
Yin et al., Metabolism, 2008
Supplements do NOT fix burnout - only structural change does. These are supportive during recovery, not curative. Typically, prioritize load reduction first.
Adaptogen that modulates cortisol and HPA axis response to chronic stress. An RCT (n=64) showed significant reduction in stress scores vs placebo.
Dose: 300mg twice daily (600mg total) for 60 days minimum
Evidence: B - One well-designed RCT in chronically stressed adults
Chandrasekhar et al., Indian J Psychol Med, 2012 · [Source]
May reduce fatigue and improve cognitive function under stress by modulating stress-response pathways.
Dose: 200mg twice daily (400mg total) for 8 weeks, standardized to 3% rosavins
Evidence: C - Open-label trial in chronic fatigue (n=100), no placebo control
Lekomtseva et al., Complement Med Res, 2017 · [Source]
Depleted by chronic stress and involved in HPA axis regulation. A systematic review found suggestive evidence for anxiety and stress reduction.
Dose: 300-400mg daily, preferably in the evening
Evidence: B - Systematic review of supplementation studies for anxiety/stress
Boyle et al., Nutrients, 2017 · [Source]
Anti-inflammatory and neuroprotective. A meta-analysis found significant antidepressant efficacy, relevant for burnout with depressive overlap.
Dose: 1-2g EPA+DHA daily, higher EPA ratio preferred for mood support
Evidence: B - Meta-analysis shows effect but notes heterogeneity
Liao et al., Transl Psychiatry, 2019 · [Source]
S. boulardii is a beneficial yeast that survives stomach acid and supports gut barrier function. Unlike bacterial probiotics, it isn't killed by antibiotics. May reduce candida colonisation through immune modulation rather than direct competition. Start after initial sugar elimi
Dose: 250-500mg twice daily with meals
McFarland LV. Systematic review and meta-analysis of Saccharomyces boulardii. World J Gastroenterol. 2010;16(18):2202-22
Caprylic acid (from coconut oil) disrupts Candida cell membranes in laboratory studies. Supplemental form provides higher concentration than dietary coconut oil. Start low: die-off reactions are common in the first 3-5 days.
Dose: 500-1000mg twice daily with food
Bergsson G et al. In vitro killing of Candida albicans by fatty acids and monoglycerides. Antimicrob Agents Chemother. 2001;45(11):3209-12
Carvacrol in oregano oil has antifungal activity against Candida species in laboratory studies. Enteric coating protects the stomach and delivers to the small intestine. Not a first-line; use after lifestyle changes if symptoms persist.
Dose: 150mg twice daily of enteric-coated capsule (standardised to carvacrol content)
Cleff MB et al. In vitro activity of origanum vulgare essential oil against candida species. Braz J Microbiol. 2010;41(1):116-23
Biotin competes with Candida for adhesion receptors. Candida binds to biotin on epithelial cells; supplementing may reduce this adhesion. Also supports metabolic health independently of antifungal effect.
Dose: 5000-10000mcg daily with food
Mock DM. Biotin: From Nutrition to Therapeutics. J Nutr. 2017;147(8):1487-1492
L. rhamnosus GG produces antimicrobial compounds and competes with Candida for gut adhesion sites. Unlike S. boulardii (yeast), this is a bacterial probiotic. Use after antifungal phase to rebuild microbiome.
Dose: 10 billion CFU daily, away from antifungals
Hatakka K et al. Probiotics reduce the prevalence of oral Candida in the elderly. J Dent Res. 2007;86(2):125-30
Dose: Multi-strain probiotic, 3 capsules twice daily during chemotherapy cycles. Discuss with your oncologist first, especially if immunocompromised.
Evidence: Grade B - RCT. In 159 breast cancer patients, probiotics during chemotherapy reduced cognitive impai
Toh et al., Eur J Cancer 2022 (PMID 34896904)
Dose: 2-3g combined EPA+DHA daily with food. Discuss with oncologist if on anticoagulants or if platelet count is low.
Evidence: Grade C - mechanistic + preclinical. Orchard et al. 2017 review: EPA and DHA protect neurons from ch
Orchard et al., Breast Cancer Res Treat 2017 (PMID 27933449)
Dose: 240-400mg curcumin extract daily between chemotherapy cycles. MUST discuss with oncologist - curcumin may interact with certain chemotherapy agents. Use bioavailable formulation (with piperine or lipid-based).
Evidence: Grade B-C - small RCT + preclinical. An RCT in cervical carcinoma patients receiving carboplatin-pac
Curcumin + cisplatin neuroprotection: PMID 25982942; GFAP reduction RCT: Springer 2023 (doi:10.1007/s13596-023-00737-8)
PEA is an endocannabinoid-like compound that modulates neuroinflammation and pain signaling. Evidence moderate. Use as adjunct to exercise, education, and sleep - not standalone.
Dose: 600mg 2-3x daily
Gabrielsson L et al., Br J Clin Pharmacol, 2016 (PMID: 27220803); Scuteri D et al., Pharmaceutics, 2022 - PEA pain meta-analysis (PMID: 36015298)
Anti-inflammatory via prostaglandin modulation. A meta-analysis of 17 RCTs found significant pain reduction in inflammatory joint pain. Most useful when inflammation contributes to pain (elevated hs-CRP). Take with food for absorption.
Dose: 2-3g combined EPA+DHA daily
Goldberg RJ, Katz J, Pain, 2007 - omega-3 pain meta-analysis (PMID: 17335973)
NMDA receptor antagonist relevant to central sensitization. Supports muscle relaxation and sleep quality - both directly relevant to pain-fog. Glycinate for sleep/relaxation, threonate if targeting cognition. Avoid oxide (poor absorption).
Dose: 200-400mg elemental magnesium daily
Shin HJ et al., Nutrients, 2020 - magnesium and pain mechanisms (PMID: 32718032)
Deficiency prevalence is 40-80% in chronic pain populations. Supplementation shows modest pain reduction in deficient individuals. TEST FIRST - do not supplement without knowing your level. Target 40-60 ng/mL.
Dose: 2,000-4,000 IU daily (test and target 40-60 ng/mL)
Wu Z et al., Public Health Nutr, 2018 - vitamin D and pain meta-analysis (PMID: 29559013)
Natural antihistamine. Best used alongside allergen avoidance and saline irrigation, not as a replacement. Full effect at 2+ weeks of consistent use.
Dose: 300mg freeze-dried leaf extract twice daily
Mittman P. Randomized, double-blind study of freeze-dried Urtica dioica in allergic rhinitis. Planta Med. 1990;56(1):44-7
Quercetin stabilises mast cells (prevents histamine release). Bromelain enhances absorption and has anti-inflammatory properties. Takes 2-4 weeks for full effect.
Dose: 500mg quercetin + 100mg bromelain twice daily on empty stomach
Mlcek J et al. Quercetin and its anti-allergic immune response. Molecules. 2016;21(5):623
Acts as mucolytic (thins mucus) and antioxidant. Breaks disulphide bonds in mucus glycoproteins. Also replenishes glutathione, reducing nasal mucosal oxidative stress.
Dose: 600mg twice daily with water between meals
De Flora S et al. Attenuation of influenza-like symptomatology and improvement of cell-mediated immunity with long-term NAC treatment. Eur Respir J. 1997;10(7):1535-41
Metformin may deplete CoQ10. Supplementation supports mitochondrial function.
Dose: 100-200mg daily
Editorial note: CoQ10 depletion mechanism is proposed but not definitively established; supplementation is precautionary
Metformin impairs B12 absorption. Supplementation prevents deficiency.
Dose: 1000mcg methylcobalamin daily
ADA recognizes B12 monitoring in metformin users
Electrolytes from food come first. Supplements are for convenience and for people with higher needs (POTS, athletes, keto dieters, hot climate). Look for balanced sodium (500-1000mg), potassium (200-400mg), and magnesium (100-200mg) per serving.
Dose: 1-2 servings daily, or DIY: 1/2 tsp salt + 1/4 tsp potassium chloride + squeeze citrus in 500ml water
Adan A. Cognitive performance and dehydration. J Am Coll Nutr. 2012;31(2):71-8. PMID: 22855911
Serum magnesium reflects only 1% of total body stores - a normal blood test doesn't rule out deficiency. Magnesium supports neural signaling, NMDA receptor regulation, sleep quality, and muscle relaxation. Glycinate is well-tolerated and supports sleep. L-threonate (Magtein) is the only form with clinical evidence for raising brain magnesium levels directly, though studies are industry-funded (PMID 36558392). Avoid magnesium oxide - poor absorption.
Dose: 200-400mg elemental magnesium daily, preferably in the evening
de Baaij JH et al. Magnesium in man: implications for health and disease. Physiol Rev. 2015;95(1):1-46. PMID: 25540137
Heavy menstrual bleeding depletes iron stores. Iron deficiency is associated with fatigue and cognitive impairment independently of anemia. Ferritin < 30 mcg/L with symptoms warrants supplementation.
Dose: Ferrous sulfate 325mg or iron bisglycinate 25-50mg daily; retest ferritin at 8-12 weeks
WHO Guideline on Daily Iron Supplementation. WHO, 2016
General anti-inflammatory support. However, the SAGE trial (a double-blind RCT in 59 young women with surgically confirmed endometriosis) found no significant pain reduction from omega-3 at 6 months.
Dose: 1-2g EPA+DHA daily
Nodler JL et al. Supplementation with vitamin D or omega-3 fatty acids in adolescent girls and young women with endometriosis (SAGE). Am J Clin Nutr. 2020;112(1):229-236. PMID: 324
Low vitamin D is common in endometriosis patients and associated with disease severity. The SAGE trial found no significant pain reduction from vitamin D supplementation at 6 months, but correction of deficiency is still standard care.
Dose: 1,000-4,000 IU daily based on serum 25(OH)D level
Nodler JL et al. Am J Clin Nutr. 2020;112(1):229-236. PMID: 32453393
An observational study in 92 women found that the NAC group showed reduced endometrioma size compared to controls. NAC is a glutathione precursor with antioxidant and anti-inflammatory properties relevant to endometriosis pathology.
Dose: 600mg three times daily
Porpora MG et al. A promise in the treatment of endometriosis: an observational cohort study on ovarian endometrioma reduction by N-acetylcysteine. Evid Based Complement Alternat M
May help with pain, sleep quality, and muscle tension. No endometriosis-specific RCT exists, but general population evidence for pain and sleep support is moderate. Pelvic pain and menstrual cramping may respond to magnesium's muscle-relaxant properties.
Dose: 200-400mg glycinate or threonate at bedtime
General evidence for pain and sleep support; no endo-specific RCT
May help with digestion of trigger foods when complete avoidance is impractical (e.g., eating out). Not a substitute for identification and avoidance of triggers.
Dose: As directed on product, with meals containing suspected triggers
Tuck CJ et al., Nutrients 2019; PMID 31336652
Supports gut barrier integrity and may reduce food reactivity over time. Multiple RCTs show symptom reduction in IBS, which overlaps heavily with food sensitivity presentations.
Dose: Minimum 10 billion CFU/day, including Lactobacillus and Bifidobacterium strains
Ford AC et al., Am J Gastroenterol 2014; systematic review of probiotics in IBS
Primary fuel for enterocytes (intestinal lining cells). May support gut barrier repair in people with suspected intestinal permeability contributing to food reactions. Preliminary evidence - small studies only.
Dose: 5g/day, taken on empty stomach
Preliminary evidence for intestinal permeability support; grade C
Natural mast cell stabilizer with anti-inflammatory properties. May reduce histamine-mediated food reactions in people whose sensitivity has a histamine component.
Dose: 500-1000mg/day, split between meals
Quercetin mast cell stabilization; grade C
Vitamin D deficiency is common in inflammatory and autoimmune conditions and may worsen immune dysregulation underlying food reactivity. Test levels before supplementing - target 30-50 ng/mL.
Dose: 2000-4000 IU/day (test 25-OH vitamin D levels first)
Immune modulation evidence; grade B. Do not supplement without testing levels first.
Meta-analysis of 7 RCTs found probiotics significantly improved cognitive function. Lactobacillus + Bifidobacterium strains modulate the gut-brain axis through short-chain fatty acid production, reducing neuroinflammation and improving barrier integrity. Fermented foods are preferable when tolerated - supplements are for those who can't.
Dose: 10+ billion CFU daily, multi-strain Lactobacillus + Bifidobacterium
Lv T et al., Neurosci Biobehav Rev, 2021 (PMID 33157148)
Meta-analysis of 9 RCTs (726 patients) found enteric-coated peppermint oil significantly reduced IBS symptoms including abdominal pain. IBS-driven gut inflammation and motility disruption contribute to brain fog through vagal signaling and systemic cytokine release. Enteric coating is essential to avoid reflux.
Dose: 180-225mg enteric-coated capsules, 2-3x daily before meals
Khanna R et al., J Clin Gastroenterol, 2014 (PMID 24100754)
RCT showed significant improvement in IBS-D symptoms and reduced intestinal permeability over 8 weeks, with a number needed to treat of 3. Glutamine is the primary fuel for enterocytes and supports tight junction repair - directly addressing the "leaky gut" mechanism that drives systemic inflammation and brain fog.
Dose: 5g three times daily
Zhou Q et al., Gut, 2019 (PMID 30108163)
Supports gut mucosal lining and intestinal barrier repair. In an RCT using a validated gut permeability model, zinc carnosine stabilized gut barrier function and reduced indomethacin-induced permeability increases. Pairs well with L-glutamine - zinc carnosine protects the mucosal layer while glutamine fuels the cells underneath.
Dose: 75mg twice daily with meals
Mahmood A et al., Gut, 2007 (PMID 16777920)
Addresses symptom, not cause. Fix diet and gut first. DAO enzyme is for when you can't avoid histamine (eating out, social situations). One RCT showed reduced migraine duration in DAO-deficient patients. Available in pea sprout-derived and porcine-derived forms.
Dose: 4,200-20,000 HDU per capsule, 15min before meals
Izquierdo-Casas et al., Clin Nutr, 2019 (PMID 29475774)
Natural mast cell stabilizer. One human study found quercetin more effective than the prescription mast cell stabilizer cromolyn at blocking mast cell cytokine release. Community reports are overwhelmingly positive. Take with bromelain for enhanced absorption.
Dose: 500mg quercetin twice daily with 100-200mg bromelain
Weng et al., PLoS One, 2012 (PMID 22470478)
Cofactor for DAO enzyme function. Vitamin C depletion is associated with elevated blood histamine levels. Community reports consistently mention it as a helpful adjunct alongside quercetin.
Dose: 500-2000mg daily in divided doses
Johnston et al., J Am Coll Nutr, 1996 (PMID 8951736)
May inhibit histamine receptor activity and mast cell tryptase. Commonly used alongside quercetin in the histamine intolerance community. Evidence is preliminary but mechanism is plausible.
Dose: 300-600mg daily freeze-dried leaf extract
Roschek et al., Phytother Res, 2009 (PMID 19140159)
Helps break down dietary histamine. Useful for eating out or when low-histamine diet isn't possible. Open-label trial showed significant symptom improvement during DAO supplementation.
Dose: 1 capsule 15 minutes before meals
Izquierdo-Casas et al., Food Sci Nutr, 2019 (PMID 31807350)
May help degrade histamine. Low risk. Small studies suggest supplemental ascorbic acid has antihistamine properties.
Dose: 500-1000mg daily
Johnston et al., J Am Coll Nutr, 1992 (PMID 1578094)
Natural mast cell stabilizer. In vitro evidence shows quercetin more effective than cromolyn at blocking human mast cell cytokine release. Take on empty stomach.
Dose: 500-1000mg twice daily, ideally with bromelain for absorption
Weng et al., PLoS One, 2012 (PMID 22470478)
Flavonoid that inhibits mast cell activation and microglial activation. Proposed to reduce neuroinflammation contributing to brain fog.
Dose: 100-200mg daily
Theoharides et al., Front Neurosci, 2015 (PMID 26190965)
Emerging evidence for cognitive benefits in menopausal women specifically. Supports brain energy metabolism during the metabolic shift. Low-cost, well-studied, minimal side effects. But it's an addition to exercise and diet, not a replacement.
Dose: 3-5g daily
Evidence: Moderate - Smith-Ryan et al., Nutrients, 2021
This isn't a wellness extra. It's a safety check for a reversible mimic of metabolic-vascular brain fog.
Dose: Common replacement strategy: 1000 mcg daily if deficient, but dose/form should follow your clinician's plan.
Evidence: Strong for metformin users and confirmed deficiency.
de Jager J et al. BMJ. 2010;340:c2181. doi:10.1136/bmj.c2181. PMID:20488910; ADA Standards of Care 2025
Use only as an adjunct if your clinician is comfortable with it, especially if you are already on glucose-lowering medication.
Dose: Often 500 mg 2-3 times daily with meals
Evidence: Moderate for glucose lowering; limited for brain fog specifically.
Evidence is adjunct-level and secondary to ADA-standard pharmacotherapy.
Reasonable only when the clinician plan is already handling glucose, blood pressure, and cardio-renal risk.
Dose: Often 600 mg daily
Evidence: Moderate for neuropathy; limited for cognition.
Adjunct-level evidence; not a substitute for medical treatment.
Useful as part of a broader cardiovascular-risk strategy, not as a standalone fog fix.
Dose: Often 1-2 g EPA+DHA daily depending on diet and clinician advice
Evidence: Moderate for cardiovascular support; mixed for cognition.
Cardiovascular and inflammatory evidence is stronger than direct metabolic-fog data.
Triggers, sleep, and meals matter more. Magnesium is a reasonable adjunct, not a replacement for proper acute treatment.
Dose: 400-600mg magnesium glycinate or citrate daily
Evidence: Moderate - AHS Grade B recommendation for prevention. Some RCT support.
Holland S et al., Neurology, 2012. PMID: 22529203; Mauskop A & Varughese J, J Neural Transm (Vienna), 2012. PMID: 22426836
Adjunct only. If you're having 4+ migraines/month, you need medical prevention, not just vitamins.
Dose: 400mg/day
Evidence: Moderate - one well-known RCT showed 50% reduction in migraine frequency. AHS Grade B.
Schoenen J et al., Neurology, 1998. PMID: 9484373; Talandashti MK et al., Neurol Sci, 2025. PMID: 39404918
Consider alongside magnesium and riboflavin as a mitochondrial support stack. Not a replacement for preventive medication if attacks are frequent.
Dose: 300mg/day (100mg three times daily)
Evidence: Moderate - one well-designed RCT showed 47.6% responder rate vs 14.4% placebo for attack frequency r
Sandor PS et al., Neurology, 2005. PMID: 15728298; Talandashti MK et al., Neurol Sci, 2025. PMID: 39404918
Omega-3 supplements ADD to an anti-inflammatory diet - they don't replace it. If you're eating inflammatory food, omega-3 is a band-aid.
Dose: 2,000mg combined daily with food (≥800mg DHA)
Evidence: Strong - Dighriri et al., Cureus, 2022: 9 RCTs showed improved cognition and cerebral blood flow. DI
Dighriri et al., Cureus, 2022. DOI: 10.7759/cureus.30091
Standard curcumin has <1% bioavailability. Must be phytosome or with piperine. Supports but doesn't replace dietary anti-inflammatory approach.
Dose: 500mg bioavailable curcumin daily
Evidence: Moderate-Strong - Meta-analysis of 11 RCTs: improved cognitive performance and reduced neuroinflamma
Zhu LN, et al. Phytother Res. 2019. PMID: 30575152. DOI: 10.1002/ptr.6257
Common deficiency linked to neuroinflammation and immune dysregulation. Check 25(OH)D levels first - target 40-60 ng/mL. Don't mega-dose without testing.
Dose: 2,000-4,000 IU daily (or as directed by test results)
Evidence: Strong for immune modulation - deficiency associated with increased inflammatory markers and worse c
Jorde R, et al. J Neurol Sci. 2019. PMID: 30889367
Glutathione precursor - reduces oxidative stress component of neuroinflammation. Well-tolerated, growing evidence in neuropsychiatric conditions.
Dose: 600mg twice daily
Evidence: Moderate - systematic review shows benefit in psychiatric and neurological conditions; mechanism wel
Dean O, et al. J Psychiatry Neurosci. 2011. PMID: 21118657
Unlike the other supplements here which reduce inflammation, Lion's Mane may actively promote nerve repair. It stimulates production of NGF and BDNF - the growth factors that rebuild neural connections damaged by chronic inflammation.
Dose: 500-1000mg dual extract (fruiting body + mycelium) daily
Evidence: Grade C - emerging. Double-blind RCT in young adults showed improved cognitive performance after chr
Docherty et al., Nutrients 2023 (PMID 38004235); NGF stimulation: Mori et al., Int J Med Mushrooms 2013 (PMID 24266378)
DHA is the primary structural fat in neuronal membranes. High-dose DHA supports membrane repair post-injury. But exercise and vestibular rehab are the primary treatments - omega-3 is adjunct. Note: This is a therapeutic dose for brain recovery. Standard maintenance dose is lower
Dose: 2,000-4,000mg DHA daily
Mills et al., Neurosurgery, 2011
Emerging evidence: creatine supports brain energy metabolism post-TBI. Sakellaris et al. 2006 RCT in children showed improvement. Low-cost, well-tolerated adjunct. Note: This evidence is from a pediatric open-label study. Adult RCT data is limited but creatine is well-tolerated.
Dose: 5g daily
Sakellaris et al., J Trauma, 2006
Post-concussion sleep disruption is common and delays recovery. Melatonin supports sleep onset without next-day sedation. RCT evidence in TBI population.
Dose: 3-5mg nightly
Grima et al., BMC Med, 2018
Test first, supplement second. Diet + prenatal vitamin may be sufficient for mild depletion. Iron infusion is faster for moderate-severe deficiency.
Dose: 65mg elemental iron every other day (better absorbed than daily). Take with vitamin C, away from tea/coffee. If ferritin <30 ng/mL and symptomatic, discuss IV iron infusion with your clinician - it repletes stores in days rather than months.
Evidence: Strong - when deficient. Supplementing without deficiency isn't beneficial and can be harmful.
Stoffel et al., Lancet Haematol, 2017 (PMID 29032957, alternate-day dosing)
Test first. If 25-OH vitamin D is below 30 ng/mL, supplementation is indicated. Most prenatal vitamins contain only 400-600 IU, which may be insufficient.
Dose: 1000-2000 IU daily (up to 4000 IU if deficient; higher doses under medical supervision). Cholecalciferol (D3) form preferred.
Evidence: B - strong deficiency prevalence data, moderate supplementation trial data. NICE NG194 recommends vi
NICE NG194; Holick MF, et al. JCEM. 2011;96(7):1911-30. PMID 21646368
Dietary fish is preferred. Supplement if intake is inadequate or if vegetarian/vegan.
Dose: 200-300mg DHA daily, or 2 portions fatty fish per week (salmon, sardines, mackerel). DHA-dominant fish oil or algae-based (vegan) supplement.
Evidence: B - ecological and RCT evidence. Mixed results on depression specifically, but consistent data on de
Hibbeln JR. J Affect Disord. 2002;69(1-3):15-29. PMID 12103448
This IS the lifestyle intervention - electrolytes are food, not pills. Listed here for clarity.
Dose: Commercial electrolyte mix (LMNT, Nuun, Liquid IV) or DIY: 1/2 tsp salt + 1/4 tsp potassium chloride + squeeze lemon in 500ml water
May support nervous system regulation and sleep quality. Evidence is for anxiety/stress broadly, not PTSD-specific. Supportive, not a treatment.
Dose: 200-400mg before bed
Boyle NB et al. The effects of magnesium supplementation on subjective anxiety and stress - a systematic review. Nutrients. 2017;9(5):429. PMID: 28445426
The only supplement with a PTSD-specific RCT. A pilot trial in veterans with PTSD and substance use disorders showed 46% reduction in PTSD symptoms vs 25% for placebo. NAC is a glutathione precursor with anti-oxidant and glutamate-modulating properties. Evidence grade: C (pilot,
Dose: 1200-2400mg daily in divided doses
Back SE et al. A double-blind randomized controlled pilot trial of N-acetylcysteine in veterans with PTSD and substance use disorders. J Clin Psychiatry. 2016;77(11):e1439-e1446. P
Emerging PTSD-specific evidence. A pilot RCT in veterans with PTSD and mild TBI found L. reuteri supplementation reduced CRP (inflammation marker) and blunted stress-induced heart rate increases vs placebo. A separate pilot (n=70) found prebiotic fiber enhanced CBT outcomes for P
Dose: Follow product dosing (strain-specific)
Brenner LA et al. Evaluation of an immunomodulatory probiotic intervention for veterans with co-occurring mTBI and PTSD: a pilot study. Front Neurol. 2020;11:1015. PMID: 33192959;
No supplement replaces movement. Exercise is the intervention. If bloodwork reveals deficiencies in iron, vitamin D, or B12, correction through supplementation is standard medical care, not a brain fog supplement strategy.
Dose: N/A
N/A
Alternative to prescription rifaximin. One comparative study (n=104, retrospective chart review) showed equivalent efficacy. Evidence Grade: B. Best used under practitioner guidance with breath test monitoring.
Dose: Berberine 500mg 3x daily + oregano oil 200mg 2x daily for 4-6 weeks
Chedid et al., Glob Adv Health Med, 2014 (PMID 24891990)
Prebiotic fiber that enhances rifaximin efficacy when used together. Clinical trial showed better eradication rates with combination therapy. Evidence Grade: B (small RCT).
Dose: 5g daily, dissolved in water or food
Furnari et al., Aliment Pharmacol Ther, 2010 (PMID 21050236)
Natural prokinetic that stimulates gut motility. Helps keep the MMC firing for recurrence prevention. Used in maintenance phase after treatment. Evidence Grade: B (mechanism-supported).
Dose: 500-1000mg with meals, or fresh ginger tea between meals
Wu et al., Eur J Gastroenterol Hepatol, 2008
Some SIBO may involve biofilm-protected bacteria resistant to standard treatment. Preliminary study (n=13) suggests biofilm disruption before antimicrobials improves outcomes. Evidence Grade: C (very preliminary).
Dose: NAC 600mg 2x daily or bismuth subnitrate - typically Phase 1 before antimicrobials
Ruscio et al., Cureus, 2025 (PMID 41394228)
Common use but limited RCT evidence for SIBO specifically. Digestive enzymes may help if malabsorption is present. S. boulardii may help rebuild microbiome AFTER treatment - avoid during active SIBO. Evidence Grade: D.
Dose: Digestive enzymes with meals; Betaine HCl if low stomach acid suspected; S. boulardii post-treatment only
Common clinical use - limited trial data
May support nervous system regulation and sleep. Supportive, not treatment.
Dose: 200-400mg before bed
Boyle et al., Nutrients 2017 (PMID 28445426)
May support mood and reduce inflammation. EPA-predominant formulations show stronger effects. Supportive, not treatment.
Dose: 1-2g EPA+DHA daily
Grosso et al., PLoS One 2014 (PMID 24805797)
Common deficiency in trauma populations who avoid outdoor activity. Low vitamin D associated with increased depression risk. Test before supplementing.
Dose: 1000-4000 IU daily (test levels first)
Anglin et al., Br J Psychiatry 2013 (PMID 23377209)
May support relaxation without sedation. One RCT showed reduced anxiety and improved sleep quality in healthy adults.
Dose: 200mg 1-2x daily
Hidese et al., Nutrients 2019 (PMID 31623400)
Dose: 225-600mg daily. Start low. Do not combine with sedating medications without medical guidance.
Evidence: Grade B - multiple RCTs for stress and anxiety. Significantly reduced cortisol levels, stress, and a
Cognitive effects: Grewal et al., Nutrients 2024 (PMC 11207027); Cortisol reduction: Salve et al., Medicine 2019 (PMID 31517876)
Most people in northern latitudes can't maintain optimal levels from sun alone, especially in winter.
Dose: 2,000-5,000 IU daily for maintenance; higher for correction under guidance
Holick, NEJM, 2007
Magnesium is required for vitamin D activation. Many people are deficient in both.
Dose: 200-400mg daily
Uwitonze & Razzaque, J Am Osteopath Assoc, 2018
Vitamin D increases calcium absorption. K2 directs calcium to bones rather than arteries. Not essential but prudent at higher D3 doses.
Dose: 100-200 mcg daily when taking D3 above 2,000 IU
van Ballegooijen et al., Int J Endocrinol, 2017
Sometimes, but they work best when they're solving a real bottleneck such as creatine availability, magnesium deficiency, sleep timing, or low omega-3 intake. They work worst when they're used to avoid diagnosis, ignore sleep apnea, or replace basic sleep, diet, and movement work. Use supplements as support tools, not as proof that you found the root cause.
If you're going to start anywhere, keep it small: one to three supplements, not fifteen. Creatine is a reasonable first move for many people. Magnesium or melatonin makes more sense when sleep is part of the story. Omega-3 fits better when diet quality or inflammatory load are the main issues. Start with the clearest fit rather than the loudest marketing.
No. They may help overlap issues like circadian drift, tension, or fragile sleep quality, but they don't treat airway collapse. If the real pattern is snoring, gasping, dry mouth, unrefreshing sleep, or an abnormal sleep study, supplements are only adjuncts to the actual sleep-apnea plan.
Usually one at a time, with at least one to two weeks between additions. That makes it possible to tell what helped, what caused side effects, and what was just noise. If you start a full stack at once, the experiment becomes almost impossible to read.
Sometimes, but only as adjuncts. Zinc only makes sense when intake is poor or deficiency is plausible. Vitamin D fits better when a real deficiency is present. Magnesium is mostly an overlap tool for sleep quality or intake gaps. None of these replace proper testosterone testing or treatment of sleep apnea, obesity, or hypogonadism.
The ONLY supplement tested in a celiac-specific fatigue trial. RCT (PMID 17693145): 30 carnitine vs 30 placebo, 2g/day for 180 days - significant fatigue reduction (p=0.0021). Celiac disease specifically reduces OCTN2 transporter expression in the gut, creating a carnitine deficit that impairs mitochondrial energy production in brain and muscle.
This is a celiac-specific metabolic mechanism, not a generic energy supplement. PMID 17693145.
The most common presenting feature of celiac disease. 14-41% still deficient even on strict GFD due to persistent enterocyte damage. 5-7x cognitive improvement after repletion in one study. Iron bisglycinate form for GI tolerance. Target ferritin >50 ng/mL.
The fastest cognitive payoff in this population. PMID 34684433, 32708019. Take separately from zinc and calcium.
Folate status may WORSEN on GFD because GF grains aren't fortified. GF cereal products also contain less magnesium than wheat equivalents. Patients need MORE supplementation after diagnosis, not less. Use methylfolate (not folic acid) - many celiac patients have MTHFR variants.
Also on the celiac page: Sublingual B12 (12-41% deficient), vitamin D (64-71% deficient), zinc (67% deficient), probiotics (14 trials).
68% of consumers don't realize supplements can contain gluten. "Starch" on labels can be wheat-derived. Use certified GF brands (Thorne, Pure Encapsulations, Garden of Life NSF GF). DPP-IV gluten-digesting enzymes DO NOT WORK - they leave immunogenic epitopes intact and give a false sense of security. Do not use as GFD substitute.
Key finding: Brain fog correlates with mucosal healing, not vitamin levels alone (PMID 24889390). GFD compliance is primary.
The most under-supplemented pregnancy nutrient. 0 of 48 commercial prenatal vitamins had adequate choline. ACOG identifies it as 1 of 11 key prenatal nutrients. Choline is the precursor to acetylcholine (memory neurotransmitter) - the fetus depletes maternal stores for brain development, potentially driving "pregnancy brain." 7-year follow-up RCT showed better child attention at 930mg/day.
You almost certainly need a separate supplement. 2 eggs/day = ~300mg. PMID 36041182, 34962672.
The most impactful single supplement when deficiency is present. Blood volume expands ~50% in pregnancy, diluting iron stores. Low ferritin directly impairs concentration even without frank anemia. But excess iron (ferritin >65) was associated with WORSE cognitive outcomes in offspring - this is one of the few supplements where overdosing has documented harm.
Test ferritin, don't guess. 27mg/day baseline; 30-60mg more only if low. PMID 32184147, 36906495.
The safest pharmacological sleep aid in pregnancy. Sleep quality is the biggest modifiable driver of pregnancy brain fog. Magnesium glycinate provides both magnesium (GABA support, cortisol regulation) and glycine (core temperature regulation for deeper sleep). Gentle on the stomach.
Also on the pregnancy page: DHA (300-600mg, prevents maternal neural depletion), iodine (thyroid support), methylfolate.
AVOID: ashwagandha (miscarriage risk), St. John's Wort (no safety data), ginkgo (bleeding), kava (liver), dong quai (uterine stimulant), ginseng, pennyroyal (potentially lethal). Vitamin A as retinol >10,000 IU/day is teratogenic. Curcumin supplements may affect uterine contractions. Lion's mane and phosphatidylserine have no pregnancy safety studies.
The bar for "interesting supplement" is much higher in pregnancy. Stick to: prenatal + choline + DHA + iron (if needed) + magnesium glycinate.
Johns Hopkins Zhang lab (Ma et al. 2021) identified these three botanicals as having direct activity against stationary phase B. henselae - the persistent forms that standard antibiotics can't kill and that cause relapse. Cryptolepis eradicated ALL persistent forms in 7 days. Chinese skullcap also binds GABA-A receptors, directly addressing the rage and anxiety hallmarks of neurobartonellosis.
Start ALL herbs at very low doses - Bartonella Herx reactions can be severe. Ma et al. DOI: 10.1097/IM9.0000000000000069.
Bartonella specifically invades and damages blood vessel lining cells. PNAS 2008 study: L-arginine directly reverses Bartonella-induced endothelial damage via nitric oxide, returning dysregulated genes to steady state. This isn't generic circulatory support - it addresses the specific vascular damage Bartonella causes. 500-1000mg 3x/day.
The only supplement with a published Bartonella-specific endothelial mechanism. PMID 18595894.
Bartonella treatment requires months of combination antibiotics with intense Herxheimer reactions. Glutathione is front-line Herx management (IV for severe episodes). Probiotics protect the gut during prolonged antibiotic destruction of microbiome. Milk thistle 1200mg/day protects the liver from rifampin hepatotoxicity. These are treatment survival essentials, not optional wellness.
Also on the Bartonella page: Curcumin (neuroinflammation), lion's mane (nerve repair).
Rifampin is the most potent CYP inducer in clinical use (per pharmacokinetic data) - it can reduce blood levels of many supplements and medications dramatically. AVOID St. John's Wort (additive CYP induction). Methylene blue (used in Mozayeni protocol) is CONTRAINDICATED with SSRIs/SNRIs/MAOIs - serotonin syndrome risk. Chinese skullcap + rifampin = double liver stress - monitor enzymes. Take minerals 2-3 hours away from doxycycline (per standard pharmacokinetic guidance).
Disclose ALL herbs and supplements to your tick-borne disease specialist.
PNAS 2018 landmark: glutathione metabolism is THE pathway most significantly affected by Borrelia burgdorferi - specific to Borrelia, not seen with other pathogens. Intracellular GSH increased 10-fold in response to Bb exposure. NAC disrupts Borrelia biofilms AND feeds glutathione production. ~70% of Horowitz's patients report improvement in fatigue, pain, and memory.
Dose: Liposomal glutathione 250-500mg 2x/day + NAC 600mg 2x/day. PMID 29444855, 23110225.
The Buhner protocol core herbs. Japanese knotweed: lowest MIC values against Borrelia (0.03-0.06%) + resveratrol crosses the blood-brain barrier for neuroprotection. Cat's claw: anti-borrelial against multiple morphological forms + enhances CD57 NK cells (commonly deficient in Lyme). Both confirmed in Johns Hopkins 2020 screening.
Start very low - Herxheimer reactions are common. PMID 32154254, 37101730. CAUTION: both interact with anticoagulants.
Lyme brain fog stack: curcumin switches activated microglia from destructive (M1) to reparative (M2) mode and lowers quinolinic acid (a neurotoxin elevated in Lyme). Lion's mane stimulates NGF (nerve growth factor), promoting repair of Lyme-damaged nerves. One reduces damage, the other promotes repair.
Also on the Lyme page: CoQ10 + NADH (mitochondrial repair), omega-3, probiotics (essential during antibiotic treatment).
Calcium, magnesium, iron, and zinc form insoluble complexes with doxycycline, reducing absorption (PMID 37101730). Take ALL mineral supplements 2 hours BEFORE or 2-3 hours AFTER doxycycline. Probiotics: 2+ hours separated from any antibiotic. St. John's Wort reduces antibiotic effectiveness - AVOID. All antimicrobial herbs should be started at very low doses to manage Herxheimer reactions.
Disclose all herbs and supplements to your Lyme-literate MD. Comprehensive review: PMID 37101730.
Most EDS brain fog is POTS-mediated cerebral hypoperfusion - your brain isn't getting enough blood when upright. Salt expands plasma volume and improves venous return. Heart Rhythm Society recommends 10-12g/day for POTS. 54% of POTS patients report salt tablets improved brain fog; 77% report IV saline helped. Pair with waist-high compression (30-40mmHg).
Start at 3g added/day, increase by 1g/day up to 12g. PMID 40843452, 23999934, 33478652.
Tulane Hypermobility Clinic breakthrough: MTHFR polymorphisms are highly prevalent in hEDS. Decreased MTHFR activity causes elevated unmetabolized folate, which upregulates MMP-2 (matrix metalloproteinase-2), which degrades collagen-stabilizing proteins. Methylfolate bypasses the broken enzyme. Patients report less pain, less brain fog, fewer allergies.
Get MTHFR tested first. Use methylfolate ONLY, not synthetic folic acid. PMID 38523329, 37095957.
20-30% of hEDS patients have comorbid MCAS where mast cells degranulate inappropriately, releasing histamine and cytokines that cause brain fog, flushing, and GI symptoms. Quercetin is more effective than cromolyn sodium at blocking mast cell cytokine release. Vitamin C is both a collagen cofactor AND mast cell stabilizer - dual role uniquely suited to EDS.
Also on the EDS page: Magnesium L-threonate (crosses BBB), iron (ferritin-guided), sublingual B12, CoQ10 (critical if on beta-blockers).
EDS is caused by defective collagen STRUCTURE (genetic), not collagen deficiency. Collagen peptides are broken down during digestion and can't fix a structural gene mutation. The Ehlers-Danlos Society doesn't recommend collagen supplements for EDS. Also: NAC can trigger histamine release in MCAS patients. Niacin (B3) is a known histamine releaser. Avoid supplements with dyes, fillers, and preservatives (MCAS triggers).
GI absorption tip: Use sublingual, liquid, or liposomal forms. Gastroparesis impairs tablet absorption. Small doses throughout the day work better than large single doses.
Food sensitivity fog is best addressed by identifying and removing trigger foods through elimination-reintroduction - not by stacking supplements. These tools only make sense after the diary, elimination trial, and celiac screening are underway. Most people don't need all of these. Pick the one or two that match your specific pattern.
L-glutamine is most relevant when the food sensitivity story includes suspected intestinal permeability - multiple new food reactions developing over months, or reactions that worsen with stress. It's the primary fuel for enterocytes (intestinal lining cells) and may support gut barrier repair. Evidence is preliminary and based on small studies, so it belongs as an adjunct to elimination, not a replacement.
Typical dose: 5g/day, taken on empty stomach. Grade C evidence.
Probiotics fit when the food sensitivity pattern overlaps with IBS-like symptoms (bloating, irregular bowel habits, food-related GI distress). Multiple RCTs show symptom reduction in IBS, which overlaps heavily with food sensitivity presentations. Choose strains including Lactobacillus and Bifidobacterium species. They may reduce food reactivity over time by improving gut barrier function.
Typical dose: Minimum 10 billion CFU/day. Grade B evidence for IBS symptom reduction.
Quercetin is most relevant when the food sensitivity has a histamine component - reactions concentrated around aged cheese, wine, fermented foods, cured meats, and leftover meals. It acts as a natural mast cell stabilizer. If your pattern doesn't look histamine-driven, this is probably not your tool.
Typical dose: 500-1000mg/day, split between meals. Grade C evidence.
Digestive enzymes fit when complete avoidance of trigger foods is impractical (eating out, social meals, travel). They're a coping tool, not a treatment - they may reduce the severity of a reaction when exposure is unavoidable but shouldn't replace identification and avoidance of your specific triggers.
Typical dose: As directed on product, taken with meals containing suspected triggers. Grade C evidence.
Vitamin D deficiency is common in inflammatory and autoimmune conditions and may worsen immune dysregulation underlying food reactivity. Test 25-OH vitamin D levels first - do not supplement blindly. Target 30-50 ng/mL. This is a deficiency correction, not a food sensitivity treatment by itself.
Typical dose: 2000-4000 IU/day after testing confirms deficiency. Grade B for immune modulation.
Commercial IgG food sensitivity tests aren't recommended by the AAAAI, EAACI, or gastroenterology societies. They measure food exposure (what you eat regularly), not sensitivity. High IgG to a food simply means you eat it often. These tests lead to unnecessary restriction and waste money that could go toward a dietitian-supervised elimination trial - which is free and more accurate.
Practical rule: elimination-reintroduction is the gold standard. AAAAI position (PMID 20451986)
EBV is controlled by your immune system. These supplements support immune function during reactivation, but they're adjuncts to the fundamentals: sleep, stress management, pacing, and not pushing through fatigue. No supplement replaces proper EBV serology testing and medical evaluation if symptoms persist.
An amino acid that competes with arginine, which herpesviruses use for replication. Evidence is from HSV (herpes simplex) studies - no EBV-specific RCTs exist. The arginine-competition mechanism is theoretically relevant to EBV, but direct evidence is limited to HSV-1 and HSV-2. Low risk to try.
Typical dose: 1,000-3,000mg daily.
Evidence: Grade C - preliminary. Mechanism extrapolated from HSV studies.
Griffith RS, et al. Dermatologica. 1987;175(4):183-190. PMID: 3115841
Supports immune function and modulates inflammatory response. Often low in chronic viral illness. Test serum 25(OH)D before supplementing - don't guess.
Typical dose: 1,000-4,000 IU/day depending on baseline. Target serum 25(OH)D 40-60 ng/mL.
Evidence: Grade B - strong immunological rationale, multiple studies showing vitamin D's role in antiviral immunity.
Aranow C. J Investig Med. 2011;59(6):881-886. PMID: 21527855
Essential for immune cell development and communication. Deficiency impairs antiviral defense. Relevant for any immune-infection cause including EBV.
Typical dose: 15-30mg/day elemental zinc. Do not exceed 40mg/day long-term (can cause copper depletion).
Evidence: Grade B - well-established role in immune function.
Calder PC, et al. Nutrients. 2020;12(4):1181. PMID: 32340216
Supports immune cell function during infection and recovery. A reasonable addition during active reactivation or recovery periods.
Typical dose: 500-1,000mg/day.
Evidence: Grade B - well-established role in immune cell function.
Calder PC, et al. Nutrients. 2020;12(4):1181. PMID: 32340216
If you've started with the minimalist stack and fog persists, ensure you've addressed sleep, diet, and blood testing first.
Approximate monthly costs above assume generic forms, not premium branded stacks.
This guide is educational, not medical advice. Consult your physician before starting any supplement.
*These statements have not been evaluated by the FDA. These products are not intended to diagnose, treat, cure, or prevent any disease.
Related Causes
Supplement strategies are commonly discussed in these cause tracks.