Illegal Melatonin Supplements Sold on Major Online Marketplaces, Including Products Claiming "10mg of Sleep"
New research has revealed that melatonin supplements are being illegally advertised and sold across some of the biggest online marketplaces, including popular sites like AliExpress, Amazon, eBay, Etsy, Superdrug Marketplace, and Temu. Some sellers have even resorted to deceptive tactics—such as inventing ingredients or altering product names—to avoid detection and continue selling these restricted products.
What is Melatonin and Why is it Regulated?
Melatonin is a hormone commonly used to help regulate sleep patterns. In the UK, melatonin is classified as a prescription-only medication due to its potential side effects and interactions with other drugs. Health professionals recommend starting doses of around 2mg, but some of the supplements observed in the research contained as much as 10mg or even 30mg, well above typical recommended dosages.
Details of the Research Findings
Consumer advocacy group Which? carried out research between October 2025 and January 2026, uncovering a range of melatonin supplements being sold despite legal restrictions:
- Supplements with melatonin levels ranging up to 10mg were found listed openly.
- One product, Balincer’s Melatonin Nighttime Sleep Aid, advertised on Temu, claimed to contain 30mg of melatonin.
- Some listings used misleading tactics, such as excluding melatonin from product names and pictures but mentioning it only in ingredient lists.
- Eight supplements sold on eBay were advertised under misleading titles like "night time fat burners" while containing melatonin.
- Sellers on Temu used spacing tricks (e.g., writing "melat onin") to evade platform detectors designed to block illegal melatonin sales.
- Other products listed melatonin only in the description, completely omitting it from titles, including a product labeled "Sleep 10mg" from the brand Xemenry, which misleadingly listed "sleep" as the ingredient instead of melatonin — breaking UK law.
Furthermore, melatonin was also found in products such as skin patches and teas, raising additional safety concerns.
Risks and Calls for Stronger Regulation
Melatonin is not suitable for everyone and can interfere with various medications—including antidepressants and contraceptives—as well as posing health risks for individuals with liver, kidney, or autoimmune conditions.
Sue Davies, head of consumer policy at Which?, expressed serious concern over the illegal marketing of melatonin. She warned:
"If shoppers buy from sellers illegally advertising melatonin, there is no telling what the products will contain—they could include excessive melatonin or other potentially harmful substances, leading to dangerous side effects."
In light of these findings, Which? is urging governments and regulatory bodies to improve oversight of the supplement industry and take unsafe products off the market swiftly.
Responses from Online Marketplaces
Several marketplaces responded to the report:
- AliExpress stated it takes product safety seriously, has removed flagged listings, and enforces strict rules prohibiting sales of medications and supplements illegally.
- Amazon said safety is a top priority, with ongoing efforts to detect and remove unsafe products, confirming removal of the highlighted items.
- eBay emphasized its active measures—including AI and regulatory cooperation—to prevent unsafe listings and noted the removal of the reported products prior to the investigation.
- Superdrug highlighted that topical melatonin-containing products are legally available in the UK and is consulting regulators for guidance.
- Temu confirmed a prohibition on melatonin sales, described their compliance systems to detect violations, and confirmed removal and penalties against sellers identified in the investigation.
Which? has reached out to Balincer, Etsy, and Xemenry for comment.
Consumers are advised to exercise caution when purchasing supplements online, especially those claiming to contain substances requiring a prescription. Consulting healthcare professionals before taking new supplements is recommended to avoid potential health risks.
For further updates on consumer safety and money matters, watch the latest episode of Sky News’ New Money.
This article is based on findings published on Tuesday, 10 February 2026 by Sky News and consumer protection group Which?.