Key Takeaways
✓ Two laboratory analyses, published in peer-reviewed journals and summarised by NCCIH, found that the melatonin in a bottle often does not match the number on the label.
✓ The 2017 analysis of 31 products found content from 83% below to 478% above the label, and serotonin in 26% of products. The 2023 analysis of 25 gummies found 22 mislabelled, with melatonin from 74% to 347% of the label.
✓ The amount matters because melatonin's effects in placebo-controlled trials change with dose: 0.3 mg and 3 mg behaved differently in a head-to-head comparison, and pooled effects peaked at 4 mg a day.
✓ What helps: a clearly stated dose per serving, a third-party testing mark or published test result, and starting from the low end of the range so a mislabelled product is a smaller surprise.
Melatonin is regulated by the FDA as a dietary supplement (PMID: 35653284), a category in which the manufacturer, not a regulator, is responsible for the number printed on the label. Two independent laboratory analyses have checked that number. This page sets out what they measured, in a table with the original PubMed records, so that the figures can be quoted with their source. It then explains why the exact amount matters more for melatonin than for most supplements, and what a shopper can check.
The 2017 analysis of 31 products
Researchers at the University of Guelph in Ontario measured melatonin and serotonin in 31 melatonin supplements of different brands and forms using liquid chromatography. Melatonin content ranged from 83% below to 478% above the labelled amount, and content varied between lots of the same product by as much as 465%. The variability was not linked to any particular manufacturer or product type. More than 71% of the products did not meet their label within a 10% margin. Eight of the 31 (26%) also contained serotonin, a related compound that was not declared on the labels, at 1 to 75 micrograms (PMID: 27855744). NCCIH summarises the same work: for most of the supplements, the amount of melatonin did not match the label (NCCIH). An editorial in the same issue of the journal gave the finding its plainest statement: what they say is often not what you get (PMID: 28095978).
The 2023 analysis of 25 gummies
A research letter in JAMA measured melatonin and CBD in 25 melatonin gummy products sold in the US (PMID: 37097362). As summarised by NCCIH, 22 of the 25 were inaccurately labelled. One product contained no detectable melatonin. In the remaining products the melatonin ranged from 74% to 347% of the labelled quantity, up to almost 3.5 times the label, and most contained more than stated, with the majority between 1.2 and 1.7 times the labelled amount (NCCIH). Gummies matter because, as NCCIH notes, many accidental ingestions by young children have involved flavored products such as gummies (NCCIH).
Table of findings
| Year and journal | What was tested | What was found | Source |
|---|---|---|---|
| 2017, Journal of Clinical Sleep Medicine (University of Guelph, Ontario) | 31 melatonin supplements of different brands and forms, bought from grocery stores and pharmacies | Content ranged from 83% below to 478% above the labelled amount. More than 71% of products were not within 10% of the label. Lot-to-lot variation within one product was as much as 465%. Serotonin was found in 8 products (26%) at 1 to 75 micrograms. | PMID: 27855744 |
| 2017, Journal of Clinical Sleep Medicine (editorial commentary on the above) | Commentary | Title summarises the finding: what the label says is often not what you get. | PMID: 28095978 |
| 2023, JAMA (Cambridge Health Alliance and University of Mississippi) | 25 melatonin gummy products sold in the US | 22 of 25 were inaccurately labelled. One contained no detectable melatonin. In the others, melatonin ranged from 74% to 347% of the labelled amount; most contained more than the label, typically 1.2 to 1.7 times. (As summarised by NCCIH.) | PMID: 37097362; NCCIH |
| 2022, MMWR (CDC) | Pediatric melatonin ingestions reported to US poison control centers, 2012 to 2021 | 260,435 ingestions in people aged 19 and under over ten years; the annual number rose 530% over the period. Context for why the amount in a product matters, not a label study. | PMID: 35653284 |
Research discussed here relates to individual ingredients and does not establish that the finished Veluna product has been clinically studied or will produce the same results.
Why the exact number matters for melatonin
For many supplements, a 50% overage is a quality problem but not a practical one. Melatonin is different, for three reasons.
- The effective range is narrow and dose-dependent. In the placebo-controlled trials pooled by a 2024 dose-response meta-analysis of 26 trials, melatonin's effect on time to fall asleep and total sleep time rose gradually with dose and peaked at 4 mg a day (PMID: 38888087). A product delivering 3.5 times its label moves a person across most of that range without their knowledge.
- Low and high doses behave differently. In a head-to-head comparison in adults over 50, 0.3 mg raised blood melatonin to the normal night-time range, while 3 mg left blood melatonin elevated into the daylight hours (PMID: 11600532). Someone who chose a 0.5 mg product on purpose is not getting what they chose if the product contains 478% of its label.
- Children are exposed to these products. US poison control centers recorded 260,435 pediatric melatonin ingestions from 2012 to 2021, and the annual number rose 530% over that period (PMID: 35653284). When a gummy contains up to 3.5 times its label, the label underestimates what a child has swallowed.
What the law requires and what it does not
Supplement labels in the US must carry a Supplement Facts panel that lists each dietary ingredient and its amount per serving, by weight of the ingredient itself (21 CFR 101.36). The rule governs what the label must say; it does not involve any agency measuring the product before sale. Independent verification exists only where a company pays for it or where a laboratory buys products off the shelf and publishes the results, which is what both analyses above did.
What third-party testing checks
Third-party programs test a product against its own label. ConsumerLab, for example, buys products at retail rather than accepting samples from the manufacturer, and a product that passes its Quality Certification Program may carry the CL seal; the testing fee is paid by the manufacturer and a product must be retested every twelve months on a random sample purchased on the open market to keep the seal (ConsumerLab; ConsumerLab). USP and NSF run certification programs with their own marks. Our comparison of USP, NSF and ConsumerLab explains what each mark does and does not cover. None of these marks is a guarantee, but a product that has been tested against its label by someone other than its maker is a different proposition from one that has not.
How to read a melatonin label
- Find the amount per serving on the Supplement Facts panel, not the front of the pack. Check the unit: 300 mcg is 0.3 mg, ten times less than 3 mg.
- Check the serving size. A label that says 1 mg per serving where a serving is two gummies gives 0.5 mg per gummy.
- Look for a third-party mark or a published test result, and check the program's own website to confirm the product is listed.
- Prefer a lot number you can find, since the 2017 analysis found lot-to-lot variation of up to 465% within single products.
- Start low. If a product turns out to contain three times its label, starting from 1 mg is a smaller surprise than starting from 5 mg. Our guide to choosing a melatonin dose covers the trial evidence at each strength, and our reference table of trial doses gives the amounts used for other ingredients.
Where Veluna fits. Veluna's two melatonin products each state one dose per serving on the Supplement Facts panel: Sleep Strips provide 1 mg of melatonin per strip, and Sleep Formula provides 2 mg per two-capsule serving. Both are made by our manufacturing partner and third-party tested, and the stated amount is the number to compare against this page.
Common questions
Does a USP, NSF or ConsumerLab mark guarantee the melatonin dose?
It means the product was tested against its label by an organisation other than the manufacturer, under that program's rules, at the time of testing. It is the best available signal, not a guarantee of every lot. The 2017 analysis found lot-to-lot variation of up to 465%, which is why programs such as ConsumerLab retest certified products every twelve months on samples bought at retail.
Is more melatonin than the label says harmful?
NCCIH states that short-term use of melatonin supplements appears to be safe for most people and that long-term safety information is lacking (NCCIH). The practical issue is that the dose you chose is not the dose you took: in the head-to-head comparison, 3 mg left blood melatonin elevated into daylight hours while 0.3 mg did not (PMID: 11600532). Talk to your doctor if you take medication or are considering melatonin for a child.
Were any of the tested products accurate?
Some were. In the 2017 analysis, more than 71% of products fell outside a 10% margin of their label, which means fewer than 29% were within it (PMID: 27855744). In the 2023 gummy analysis, 22 of 25 products were inaccurately labelled as summarised by NCCIH, which leaves 3 that were not (NCCIH). Neither paper's abstract names the accurate brands.
Do these findings apply outside the United States?
The 2017 analysis came from a Canadian university laboratory and the 2023 analysis tested products sold in the US. Both are laboratory measurements of specific products at a specific time, not surveys of every product on the market, and the authors of the 2017 paper call for manufacturers to tighten controls so that products meet their label and are free of serotonin (PMID: 27855744).
References
- Erland LA, Saxena PK. Melatonin natural health products and supplements: presence of serotonin and significant variability of melatonin content. J Clin Sleep Med. 2017;13(2):275-281. PMID: 27855744
- Grigg-Damberger MM, Ianakieva D. Poor quality control of over-the-counter melatonin: what they say is often not what you get. J Clin Sleep Med. 2017;13(2):163-165. PMID: 28095978
- Cohen PA, Avula B, Wang YH, Katragunta K, Khan I. Quantity of melatonin and CBD in melatonin gummies sold in the US. JAMA. 2023;329(16):1401-1402. PMID: 37097362
- National Center for Complementary and Integrative Health. Melatonin: What You Need To Know. nccih.nih.gov
- Cruz-Sanabria F, Bruno S, Crippa A, et al. Optimizing the time and dose of melatonin as a sleep-promoting drug: a systematic review of randomized controlled trials and dose-response meta-analysis. J Pineal Res. 2024;76(5):e12985. PMID: 38888087
- Zhdanova IV, Wurtman RJ, Regan MM, Taylor JA, Shi JP, Leclair OU. Melatonin treatment for age-related insomnia. J Clin Endocrinol Metab. 2001;86(10):4727-4730. PMID: 11600532
- Lelak K, Vohra V, Neuman MI, Toce MS, Sethuraman U. Pediatric melatonin ingestions, United States, 2012-2021. MMWR Morb Mortal Wkly Rep. 2022;71(22):725-729. PMID: 35653284
- US Food and Drug Administration. 21 CFR 101.36, Nutrition labeling of dietary supplements. ecfr.gov
- ConsumerLab.com. Quality Certification Program. consumerlab.com
- ConsumerLab.com. About ConsumerLab.com. consumerlab.com
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. This article is for informational purposes only and does not constitute medical advice. Talk to a healthcare professional before starting any supplement, especially if you are pregnant, nursing, taking medication, or have a medical condition.
