Risks Associated with Purity & Potency of Melatonin Supplements

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May 16, 2024

By Joie Meissner ND, BCB-L

Supplement manufacturers vary in terms of the consistency in the quality, purity and potency. Some manufacturers do batch testing of finished products using third-party labs and will provide consumers with product test-results.

In 2017, Canadian researchers purchased 31 melatonin supplements spanning 16 different brands from local grocery stores and pharmacies in Guelph, Ontario. They analyzed the supplements using ultra-performance liquid chromatography methods to electrochemically quantify melatonin and serotonin content. They found that melatonin supplements have high lot-to-lot variability in melatonin content and that some supplements were contaminated with the mood hormone serotonin. The lot-to-lot variability within a particular supplement product “varied by as much as 465%” with some chewables containing five to six times more melatonin than that listed on the label. “Melatonin content did not meet label within a 10% margin of the label claim in more than 71% of supplements and an additional 26% were found to contain serotonin,” the researchers concluded. ¹

In Canada, serotonin is a strictly controlled substance because relatively low doses of serotonin can lead to overdose and can lead to serious side effects. ^{2, 3, 4} It is not a drug used in the United States.

Links to more information on melatonin:

Though many supplement manufacturers display the word ‘serotonin’ on their labels making it appear that they might contain actual serotonin, serotonin cannot be purchased in supplement form. What the supplements actually contain could be precursor chemicals like 5-HTP or botanicals that may boost serotonin levels. SSRI antidepressants don’t contain serotonin either; instead, they act to boost serotonin levels by interfering with their metabolism. Taking SSRIs with other medications that lead to dangerous serotonin elevations can cause serotonin syndrome—a potentially deadly condition.

American researchers at the Cambridge Health Alliance and the University of Mississippi—one of whom receives research support from Consumers Union, the policy arm of Consumer Reports—performed a chemical analysis of 25 melatonin-CBD-combo gummy formulations that were purchased from online sellers in 2021. Using ultra high-performance liquid chromatography methods, the researchers were looking to determine the quantities of melatonin and CBD, and to see if serotonin was present in any of the supplements. ⁵

The American researchers determined that “only 3 products (12%) contained a quantity of melatonin that was within ±10%” of what was listed on their labels. One of the supplements tested did not contain any detectable levels of melatonin. In products that contained melatonin, 88% were “inaccurately labeled” with the actual quantity of melatonin ranging “from 74% to 347% of the labeled quantity.” “The actual quantity of CBD ranged from 104% to 118% of the labeled quantity. Serotonin was not detected in any product.” ⁶

The researchers concluded that; “to our knowledge, this is the first US study to quantify melatonin in over-the-counter melatonin products. A Canadian study had similar results: analysis of 16 Canadian melatonin brands found that the actual dose of melatonin ranged from 17% to 478% of the declared quantity.” ⁷

In rare cases, manufacturers may include animal-derived melatonin in supplements. Animal products may be included in other hormonal supplements like natural thyroid hormone replacement supplements. Melatonin, thyroid, testosterone, estrogen and any other hormonal products derived from animal sources carry the risk of contamination. Animal-derived melatonin could come from the pineal-gland located in the brains of an animal such as a cow or other animal. Scientific journal articles in the late 1990’s report on rare cases of product contamination. But the vast majority of manufacturers synthesize melatonin in a lab. ^{8, 9}

Some melatonin preparations were found to contain contaminants that were linked to eosinophilia-myalgia syndrome—a rare but, in some cases, life-threatening condition, according to research from the late 1990’s ^{10, 11, 12}    

An internet search of the scientific literature and medical journals conducted using artificial intelligence found no confirmed case reports of EMS resulting from taking contaminated melatonin within the last 40 years.

Any given supplement can contain harmful impurities. There have been a number of studies showing that products don’t contain the ingredients in the amounts listed on the labels. Safety-conscious supplement manufacturers use spectrometry or other proven methods to batch test their final products for purity and potency. The most reputable companies do batch testing of final products using third-party labs with some offering a certificate of analysis to consumers who request it.

Always consult a physician or qualified healthcare provider before starting or stopping any medication or supplement.

To find out about possible adverse reactions and side effects of melatonin, click link below:

Some Side Effects & Adverse Effects of Melatonin

Care informed by the understanding that emotional and physical wellbeing are deeply connected

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Citations

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1. 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):275-280. doi:10.5664/jcsm.6462 PubMed Google Scholar Crossref ↩︎
2. Prakash S, Patel V, Kakked S, Patel I, Yadav R. “Mild serotonin syndrome: a report of 12 cases.” Ann Indian Acad Neurol. 2015;18(2):226–230. [PMC free article] [PubMed] [Google Scholar] ↩︎
3. Boyer EW, Shannon M. “The serotonin syndrome.” N Engl J Med. 2005;352(11):1112–1120. [PubMed] [Google Scholar] ↩︎
4. 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):275-280. doi:10.5664/jcsm.6462 PubMed Google Scholar Crossref ↩︎
5. Cohen PA, Avula B, Wang Y, Katragunta K, Khan I. “Quantity of Melatonin and CBD in Melatonin Gummies Sold in the US.” JAMA. 2023;329(16):1401–1402. doi:10.1001/jama.2023.2296 JAMA/2804077 ↩︎
6. Cohen PA, Avula B, Wang Y, Katragunta K, Khan I. “Quantity of Melatonin and CBD in Melatonin Gummies Sold in the US.” JAMA. 2023;329(16):1401–1402. doi:10.1001/jama.2023.2296 JAMA/2804077 ↩︎
7. Cohen PA, Avula B, Wang Y, Katragunta K, Khan I. “Quantity of Melatonin and CBD in Melatonin Gummies Sold in the US.” JAMA. 2023;329(16):1401–1402. doi:10.1001/jama.2023.2296 JAMA/2804077 ↩︎
8. Naylor S, Gleich GJ. “Over-the-counter melatonin products and contamination.” Am Fam Physician. 1999;59:284, 287-8. View abstract. ↩︎
9. Avery D, Lenz M, Landis C. ‘Guidelines for prescribing melatonin.” Ann Med. 1998;30:122-30. View abstract. ↩︎
10. “Melatonin Monograph” NatMed Pro Therapeutic Research Center database last modified on 3/7/2024, accessed March 2024 ↩︎
11. Williamson BL, Tomlinson AJ, Naylor S, Gleich GJ. “Contaminants in commercial preparations of melatonin.” Mayo Clin Proc. 1997;72:1094-5. View abstract. ↩︎
12. Williamson BL, Tomlinson AJ, Mishra PK, et al. “Structural characterization of contaminants found in commercial preparations of melatonin: similarities to case-related compounds from L-tryptophan associated with eosinophilia-myalgia syndrome.” Chem Res Toxicol. 1998;11:234-40. View abstract. ↩︎