Melatonin, commonly used as a sleep aid, has become widely available as a dietary supplement in the United States, with numerous products tailored specifically for children. Although melatonin has gained popularity, concerns about safety and dosage accuracy have increased, particularly as reports highlight rising cases of unintentional ingestion in children. A recent study aimed to analyze the melatonin content in various supplements marketed for children and examined the accuracy of labeling across different product forms.
Testing Melatonin Supplements for Children
The study analyzed 110 melatonin products marketed for children, spanning multiple forms, including gummies, liquids, chewable and fast-dissolving tablets, general tablets, capsules, and other edibles. These products were purchased from major U.S. retailers and examined to determine if the melatonin content matched the amounts indicated on their labels. An advanced liquid chromatography–tandem mass spectrometry (LC-MS/MS) technique was used, which is particularly reliable for identifying melatonin and two of its breakdown products—AFMK and AMK—across various formulations.
Melatonin Content and Labeling Accuracy
The study found melatonin in 98% of the tested products, with a wide range of concentrations:
- Concentration Range: The melatonin content varied significantly, from as little as 0.017 mg/g to as much as 130 mg/g. In terms of servings, this translated to a range of 0.042 mg to 50 mg per serving.
- Label Discrepancies: Only half of the products (50%) contained melatonin within the range specified on their labels. Some products had melatonin levels far below the labeled amount (0%–76%), while others contained up to 667% of the indicated quantity.
These discrepancies highlight a concerning inconsistency in melatonin labeling across products, especially for children’s supplements. The variability may stem from differences in stability or manufacturing practices, particularly as melatonin can degrade when exposed to light, heat, and air.
Melatonin Degradation: Stability and Breakdown
While melatonin can degrade, particularly under high pH, oxygen, and light exposure, the study found no evidence of degradation across the analyzed products, even after 12 months. The study monitored levels of AFMK and AMK, the main degradation products, which were present in only a small number of samples at low concentrations. This finding suggests that the supplements generally maintained melatonin stability over time.
Product Forms and Labeling Variations
Gummy supplements made up nearly half of the products tested, reflecting consumer preference, particularly among parents seeking convenient, child-friendly formulations. However, other product forms, such as tablets and capsules, exhibited greater accuracy in melatonin content relative to label claims. Only a small proportion of other edible products, including chocolate pieces and jellybeans, exceeded the labeled amounts by as much as 667%.
In addition to discrepancies in melatonin content, the study found that product labeling was inconsistent regarding age recommendations. Though 70% of the products were labeled for children, some lacked clear usage instructions for age groups. This could lead consumers to mistakenly administer adult-formulated melatonin to children, highlighting the importance of clearer labeling.
Additional Ingredients and Consumer Considerations
Some melatonin supplements also included additional ingredients such as herbal extracts (ashwagandha, passionflower) and vitamins, which can influence consumer purchasing. These co-formulated products, however, underscore the need for heightened consumer awareness, as they may contain varying active ingredients that interact with melatonin or influence its effectiveness.
Implications for Safety and Future Research
The variability in melatonin concentrations calls for improved quality control and labeling practices within the dietary supplement industry. For parents and caregivers considering melatonin for children, the inconsistent accuracy on labels poses potential risks, as administering an incorrect dosage can lead to unintended side effects and poisoning. Melatonin is widely recognized for its role in sleep support, but its effects, particularly in children, should be managed with careful attention to dose.
Given these findings, further research is recommended to address the factors influencing melatonin variability in supplements. This would include more comprehensive studies on product stability across diverse formulations and conditions. Manufacturers should also implement more stringent measures to ensure label accuracy, ensuring consumer safety and trust in dietary supplements, especially those intended for children.
Reference
- Pawar RS, Coppin JP, Khanna S, Parker CH. A Survey of Melatonin in Dietary Supplement Products Sold in the United States. Drug Test Anal. 2024 Oct 31.