Melatonin seems like the simplest supplement on the shelf: one active substance, a small tablet, a low price. However, independent analyses time and again show that the actual content of the hormone in products can differ several-fold from what is written on the package. The editorial team examined which lines on the label really matter and which are just marketing.
Why Melatonin Quality Is Not a Trifle
Melatonin is a hormone produced by the pineal gland in the dark hours of the day. It does not «switch off» the brain like a sleeping pill, but gives the body a signal that night has come and helps shift the internal clock. That is why the dose and the timing of intake are critically important for it: too large or unpredictable an amount can cause morning drowsiness and disrupt the rhythm instead of adjusting it.
The problem is that in many countries melatonin is sold as a dietary supplement, not as a medicinal product. For supplements, the requirements for controlling the content of the active substance are much softer than for drugs. The manufacturer is responsible for the safety of the product, but no one requires regular independent testing of each batch.
The Canadian study by Erland and Saxena (2017) analyzed 31 melatonin products. The actual content ranged from about 83% below to 478% above the stated amount, and between batches of the same product the discrepancies reached hundreds of percent. In some samples serotonin was found — a substance these products should not have contained at all.
A similar picture was shown by the work of Cohen and colleagues (2023) regarding chewable melatonin gummies sold in the USA: the hormone content ranged from 74% to 347% of the stated amount, and in several products cannabidiol was found, not listed as a main ingredient. For a person trying to select the minimum effective dose, such fluctuations nullify all the logic.
That is exactly why the choice of melatonin should begin not with the price or the design of the jar, but with checking how transparently the manufacturer describes the composition and whether the product has independent confirmation of quality.
Dose per Serving: Less Often Means Better
The first thing worth finding on the label is the amount of melatonin in one tablet or capsule. On the market there are products from 0.5 to 10 mg and even more. Intuitively it seems that a higher dose works more strongly, but for melatonin this is not so: the receptors become saturated at relatively small amounts, and the excess only circulates in the blood longer.
The European Food Safety Authority (EFSA) recognized two claims for melatonin as substantiated: reduction of the time to fall asleep when taking 1 mg before bed and relief of the subjective sensations of jet lag when taking at least 0.5 mg before bed on the day of arrival and for several following days. That is, the evidence base in the EU is built around doses of about 0.5–1 mg, not 5–10 mg.
The prescription melatonin drug with prolonged release, approved by the European Medicines Agency for treating insomnia in people aged 55 and over, contains 2 mg. This is another benchmark: even the medicinal form for clinical use does not use «megadoses».
Therefore it is more convenient to choose a product with a small dose per serving or tablets with a score line that can be divided. This makes it easier to start with the minimum and, if needed, gradually select your own amount, rather than immediately get a dose the body does not need.
| What is written on the label | How to interpret it |
|---|---|
| 0.5–1 mg per serving | Corresponds to the doses on which the EFSA claims are based |
| 2–3 mg per serving | A moderate dose; convenient if the tablet can be divided |
| 5–10 mg per serving | A high dose, more often causes morning drowsiness; not worth choosing without need |
| «Proprietary blend» without mg of melatonin | It is impossible to assess the dose — a reason to refuse the purchase |
Release Form and Excipients
The second important characteristic is the type of release. The regular (fast) form gives a concentration peak within about an hour and is best suited to those who have difficulty specifically falling asleep. The prolonged form releases the hormone gradually over several hours and is designed for those who often wake up in the middle of the night. On the label this is indicated by the words «slow», «prolonged», «extended/prolonged release», or «time release».
Sublingual tablets, sprays, and drops are absorbed a little faster, but have no significant advantage in an ordinary situation. Chewable gummies are convenient, but it was precisely they that, in the study by Cohen and colleagues, showed the greatest discrepancies between the stated and actual dose, and they also contain sugar and flavorings.
Look carefully at the full list of ingredients. Many «sleep» products combine melatonin with plant extracts (valerian, passionflower, chamomile), amino acids (L-theanine, 5-HTP, glycine), or magnesium. Combinations are not necessarily bad, but the more components there are, the harder it is to understand what exactly acts and what may cause an unwanted reaction.
Special attention — to 5-HTP and tryptophan. They are precursors of serotonin, so for people taking SSRI antidepressants or other serotonergic drugs, such combinations without consulting a doctor are unsuitable.
Label Checklist: What Must Be Present
A quality label is above all complete and verifiable information. The absence of basic data does not prove that the product is bad, but it indicates that the manufacturer does not consider transparency a priority.
- The exact amount of melatonin in mgper single tablet or capsule, not just per «serving of several units».
- The type of release— fast or prolonged.
- The full compositionwith excipients, colorants, sweeteners.
- Batch number and expiration date; melatonin is sensitive to light and moisture, so opaque packaging also matters.
- Manufacturer and country of manufacture, contacts for inquiries.
- Warnings: not for pregnant and breastfeeding women, do not drive after taking, consult a doctor.
A good sign is the presence of independent third-party certification (for example, USP Verified, NSF Certified for Sport, Informed Sport). Such programs verify the correspondence of the content to what is stated and the absence of contaminants. For athletes who undergo doping control, certificates such as Informed Sport are especially valuable: melatonin is not banned by WADA, but impurities in the product are a risk.
Another useful step is a certificate of analysis (Certificate of Analysis, COA) for a specific batch. Some manufacturers publish it on their website or provide it on request. If a company refuses to provide such data, this is a strong argument in favor of another brand.
Typical Marketing Traps
Labels such as «natural», «plant-based», or «from cherry» are often misleading. The vast majority of melatonin in supplements is synthetic, and that is normal: synthetic melatonin is chemically identical to that produced by the pineal gland and has predictable purity. Melatonin of animal origin (from the pineal glands of animals) is practically not used today because of contamination risks.
Wording like «maximum strength» or «10 mg for deep sleep» appeals to the false logic of «more is better». For melatonin the exact timing of intake and a regular regimen are more important than a large dose. Moreover, high doses more often cause headache, vivid dreams, and morning sluggishness.
Be cautious with promises of a therapeutic effect: «will cure insomnia», «replaces a sleeping pill». Chronic insomnia, according to the clinical guidelines of the American Academy of Sleep Medicine (2017), requires above all cognitive behavioral therapy, and melatonin has a limited evidence base for this condition.
Finally, one should not consider children's forms safer just because of bright packaging. Gummies with melatonin must be stored out of the reach of children, and giving melatonin to a child is advisable only on the recommendation of a pediatrician.
Editorial Conclusions
Quality melatonin is a product with a clearly stated small dose per unit, an understandable type of release, a minimum of unnecessary components and, ideally, independent certification. It is precisely these parameters that affect the result more than the brand or the price.
Data from independent analyses show that a supplement's label cannot always be taken at its word. Therefore preference goes to manufacturers who publish certificates of analysis and undergo third-party inspections.
Even the best product will not compensate for a chaotic regimen, bright screen light in the evening, and late coffee. Melatonin is an auxiliary tool, not a replacement for sleep hygiene.
We also recommend reading our materials «Melatonin: Forms and Which to Choose», «Side Effects of Melatonin», and «Melatonin or Magnesium: What's the Difference».
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.
- Cohen PA, Avula B, Wang YH, Katragadda K, Khan I. Quantity of melatonin and CBD in melatonin gummies sold in the US. JAMA. 2023;329(16):1401–1402.
- EFSA Panel on Dietetic Products, Nutrition and Allergies. Scientific Opinion on the substantiation of a health claim related to melatonin and reduction of sleep onset latency. EFSA J. 2011;9(6):2241.
- EFSA Panel on Dietetic Products, Nutrition and Allergies. Scientific Opinion on the substantiation of health claims related to melatonin and alleviation of subjective feelings of jet lag. EFSA J. 2010;8(2):1467.
- Sateia MJ, Buysse DJ, Krystal AD, et al. Clinical practice guideline for the pharmacologic treatment of chronic insomnia in adults: an American Academy of Sleep Medicine clinical practice guideline. J Clin Sleep Med. 2017;13(2):307–349.
- Ferracioli-Oda E, Qawasmi A, Bloch MH. Meta-analysis: melatonin for the treatment of primary sleep disorders. PLoS One. 2013;8(5):e63773.
- European Medicines Agency. Circadin (melatonin) 2 mg prolonged-release tablets: summary of product characteristics.
Andriy Melnyk
A strength-sports coach and author of programs for beginner and intermediate levels. Writes about training planning.
