What alpha-MSH measures and why the sample matters
You may hear that any result below 35 pg/mL proves CIRS or that 60 to 81 pg/mL is an ideal level. Current laboratories do not agree with that range. Before interpreting the number, identify the exact alpha-MSH assay, current report interval, collection kit, tube, preservative, processing time, freezing, medicines, and reason for testing. This reduces the risk of treating an outdated cutoff or a mishandled sample as diagnostic evidence.
Biology
One peptide in the melanocortin system
The body makes alpha-MSH from a larger protein called POMC. It helps control skin color and energy balance. One blood sample cannot show all of its work in the body.
Specimen
The sample needs uncommon handling
The current assays use frozen EDTA plasma, with a special preservative for Labcorp or rapid separation for ARUP. A routine tube and routine transport may not be usable.
Range
The familiar 35 to 81 range is historical
That interval appeared as Labcorp's range in a 2006 paper. Current Labcorp lists 0 to 40 pg/mL and ARUP gives the interval on the report.
Evidence
The CIRS evidence does not validate a diagnosis
The often-cited study selected 28 symptomatic exposed patients, had no independent diagnostic control group, and did not repeat MSH after treatment.
Alpha-MSH has real roles in melanocortin biology. That doesn't prove a commercial blood test can check hypothalamus function, identify a building, explain several symptoms together, or choose treatment.
Save this test
Save the assay with the number
My Fog keeps the dated range, collection kit, frozen handling, medicines, and clinical question with the result. That lowers the risk of misreading a bad sample or old cutoff.
Repeat only when the same assay and correct frozen collection answer a named question. Do not repeat until the value fits an internet target.
What can change how this result is read?
Current test directories do not provide validated child, pregnancy, or older-adult diagnostic thresholds for CIRS or brain fog. Use the report's own range. Treat age, sex, pregnancy, medicines, and the reason for testing as context, not a way to invent an ideal level.
Infants and children
Do not use an adult internet cutoff for a child. A pediatric clinician should first check growth, appetite, skin color, adrenal symptoms, sleep, development, medicines, and family history. These findings may point to a standard hormone or genetic assessment.
Teenagers and adults
Record time of day, fasting, medicines, recent illness, radioisotope exposure, sleep, weight or appetite change, skin changes, and the original reason for testing. A specialty peptide panel shouldn't replace the usual symptom-based checks.
Women, pregnancy, and postpartum
Older human research found pregnancy-related changes in immunoreactive alpha-MSH, but it does not provide a current pregnancy interval for these commercial assays. Tell the obstetric clinician and laboratory about pregnancy or postpartum timing and never stop blood-pressure or steroid medicine for this draw without the prescriber's instructions.
Men
Neither current directory provides a separate male target. Go by the testing lab's range and the reason for the test, not an ideal value based on sex, body size, or skin color.
Older adults
Many medicines, steroid treatment, blood-pressure drugs, sudden illness, cancer, and pituitary or adrenal disease can affect this result. Common causes of thinking changes may matter more than an alpha-MSH flag. Check those causes directly.
How to get a usable frozen alpha-MSH sample
Before the appointment, ask whether the order is specifically for alpha-melanocyte-stimulating hormone in plasma. It is not follicle-stimulating hormone, melanin, ACTH, a POMC genetic test, an alpha-subunit pituitary tumor marker, or a melanotan product.
Ask the collection site to obtain and read the performing laboratory's kit and instructions before the draw. Labcorp requires its collection kit, EDTA plasma collected with Trasylol, separation, and freezing. ARUP accepts lavender or pink EDTA blood, requires separation from cells within two hours, immediate freezing, and a separate sample for any other tests.
Ask the prescriber whether any medicine instruction applies to you. ARUP says steroid, ACTH, or blood-pressure medicine may be discontinued if possible for at least 48 hours, but you should never stop these medicines yourself. ARUP prefers a morning fasting sample, but other labs may give different instructions.
Bring the complete earlier report if this is a repeat. Record the performing laboratory, method, unit, interval, time of day, fasting status, medicines, pregnancy, recent radioisotope exposure, acute illness, and whether the specimen stayed frozen.
Confirm alpha-MSH
Match the exact order name, specimen, performing laboratory, method, unit, and current interval. Several unrelated pituitary and pigmentation tests contain alpha or MSH in their names.
Use the performing laboratory's kit
The collection site should obtain the required tubes and preservative before the appointment. Labcorp's assay requires a Trasylol-labeled collection, while ARUP's forwarded assay uses EDTA plasma without publishing one fixed interval online.
Separate plasma promptly
Follow the performing laboratory's deadline. ARUP requires plasma separation as soon as possible or within two hours. Do not leave the sample as ordinary whole blood while waiting for routine processing.
Freeze and transport correctly
Transfer the required plasma volume to the specified plastic transport tube, freeze immediately, and keep it frozen. Labcorp rejects specimens that arrive unfrozen and ARUP calls frozen transport critical.
Keep the interval with the result
Save the value, pg/mL unit, report interval, report date, method, and performing laboratory together. Do not replace the report interval with 35 to 81 pg/mL from a 2006 paper or a CIRS website.
Ask what the number changes
Ask which condition the clinician is checking. Also ask which usual tests and exam findings matter, and what each possible alpha-MSH result would change.
How to understand an alpha-MSH result
Start with the exact test, performing laboratory, method, report date, unit, and interval. Then check the collection kit, preservative, separation time, freezing, transport, medicines, and rejection comments. Only then should a specialist read the number alongside the reason for the test.
Inside this assay's interval
Inside the current report interval
The value is inside that assay's interval. It does not rule out a damp building, supported mold-related respiratory illness, a sleep or endocrine problem, inflammation, or another cause of brain fog.
Near a limit or changed interval
Near a limit or discordant with an older interval
Check the assay, report date, specimen, preservative, freezing, and medicine instructions. You can't chart results across labs or methods just because both reports say alpha-MSH.
Outside this assay's interval
Outside the current report interval
First check that the lab accepted and handled the sample correctly. A true low or high result can have many causes. Read it with symptoms, an exam, usual tests, medicines, and the reason for the test.
A value below 35 pg/mL is not automatically low
The 35 to 81 pg/mL range came from the laboratory interval used in a 2006 study. Labcorp now lists 0 to 40 pg/mL, while ARUP reports a method-specific interval with the result. A number from one lab method on one date can't become a universal CIRS cutoff.
See research details
These values describe different assays, dates, and selected populations. Keep each number with the source that produced it.
Use the dated interval on the original report. A value of 30 pg/mL can be inside one current interval and below an older one, so the number only makes sense with its laboratory and method.
Labs can measure alpha-MSH, but the number isn't proven useful for CIRS, mold, or brain fog. Ask what established diagnosis or test is doing the confirming.
This was not a diagnostic-accuracy study with an independent control population. The 25 abnormal results cannot be called population sensitivity, specificity, or proof that low MSH identifies mold exposure.
A fragile peripheral plasma immunoassay cannot tell how much alpha-MSH is acting at a person's hypothalamic receptors or explain cognition, appetite, pain, sleep, or pigmentation by itself.
Use water damage, dampness, musty odor, inspection, and supported respiratory or allergy evaluation for those questions. Do not use alpha-MSH to name a building, mold species, exposure dose, or safe return date.
What to do after an alpha-MSH result
There's no proof that any food, supplement, light treatment, or home plan fixes an alpha-MSH result. Check the report and sample handling first. Keep prescribed treatment safe, and investigate symptoms or building problems directly.
Audit the sample before repeating it
Save the collection kit, tube, preservative, processing time, frozen status, rejection comments, performing laboratory, method, value, unit, and interval. Ask the laboratory whether a specimen that missed any required step remains interpretable.
Keep medicine changes with the prescriber
If the laboratory prefers a pause in steroids, ACTH, or blood-pressure medicine, ask the prescriber whether that is safe and how to do it. Do not skip an essential medicine to improve a laboratory number.
Check the symptom that needs treatment
Check when brain fog started and what changed: sleep, appetite, weight, headaches, pain, skin, thirst, urination, periods, pregnancy, mood, medicines, or illness. Ask which usual hormone, metabolic, sleep, nutrition, medicine, vision, or nerve check fits the symptoms.
Deal with dampness as a building problem
If you see or smell dampness or mold, fix the water source and dry wet materials. Take photos of damage. Get qualified help if the source is hidden or the area is large. Do not wait for an alpha-MSH result.
Do not use tanning peptides to change MSH
Melanotan products sold as nasal sprays, injections, tablets, or tanning agents are not a treatment for a low alpha-MSH report. Australia's TGA warned in 2025 that unapproved melanotan products may be counterfeit or poor quality and can cause serious harms. They also do not replace sun protection.
Do not use one alpha-MSH result to start melanotan, tanning or UV exposure, binders, antifungals, supplements, hormones, steroids, prescription treatment, restrictive diets, or major remediation. New severe headache, vision loss, fainting, confusion, facial droop, speech trouble, one-sided weakness, severe vomiting, chest pain, or severe breathlessness needs urgent medical assessment.
What to save for a specialist visit
Keep these together
- Full dated report, exact alpha-MSH name, performing laboratory, method, value, pg/mL unit, and printed interval
- Collection kit, tube, preservative, draw time, time to separation, transfer tube, freeze time, transport, and rejection comments
- Fasting, time of day, steroid, ACTH and blood-pressure medicines, pregnancy or postpartum timing, radioisotope exposure, and recent illness
- Symptoms and timing, building or exposure evidence, standard endocrine or medical tests, and clinician interpretation
- What decision the result changed, whether a repeat is planned, and the exact laboratory and collection conditions required for comparison
Question for the visit
“Was the correct alpha-MSH assay collected and frozen properly, does the dated report use the current interval, could medicines or handling affect it, and what established test or diagnosis confirms the interpretation?”
Sources for MSH (Melanocyte-Stimulating Hormone)
Current 0 to 40 pg/mL interval, RIA, Trasylol kit, frozen stability, rejection rules, radioisotope issue, and manufacturer research-use limitation.
Current EDTA-plasma collection, medicine and fasting preference, two-hour separation, critical freezing, by-report interval, turnaround, and forwarded-assay status.
Quest/Pan discontinuation, move to ARUP and Interscience, EDTA collection, two-hour processing, immediate freezing, and by-report interval.
POMC processing, alpha-MSH and beta-MSH context in humans and rodents, central melanocortin receptors, appetite, and human genetic evidence.
Very low human circulating alpha-MSH, local skin production, pigmentation biology, and limits of pituitary assumptions.
Selected water-damaged-building cases, old 35 to 81 pg/mL interval, 25 abnormal results, absent diagnostic controls, and no repeat MSH measurement.
Evidence-based medical diagnostic boundaries for indoor mold exposure.
No health-based indoor mold standards, visual and odor assessment, moisture correction, and environmental testing limits.
Pregnancy-related immunoreactive alpha-MSH research, not a current commercial pregnancy interval.
Unapproved online melanotan forms, quality uncertainty, adverse effects, cancer concern, and lack of sun protection.
See each claim's sources
range
Labcorp's current alpha-MSH RIA lists 0 to 40 pg/mL, requires a Trasylol collection kit and frozen specimen, and carries a research-use limitation from the assay manufacturer.procedure
ARUP's forwarded RIA uses EDTA plasma separated within two hours and frozen immediately, reports its interval by report, and prefers a morning fasting specimen.range
The 35 to 81 pg/mL interval used in the 2006 water-damaged-building study was identified as the Labcorp interval at that time and is not a universal current target.limitation
The 2006 study found abnormal baseline MSH in 25 selected cases but did not establish sensitivity, specificity, a general-population cutoff, or MSH response to treatment.interpretation
Peripheral plasma alpha-MSH is not a direct measurement of melanocortin signaling inside the human brain.limitation
A plasma alpha-MSH result cannot diagnose indoor mold exposure, identify a contaminated building, or establish CIRS by itself.safety
Unapproved melanotan tanning products are not a treatment for a low alpha-MSH report and can cause serious harm.