Melatonin is a hormone that is naturally produced in the brain to help control our body's sleep/wake cycles.
In Australia, products containing melatonin are scheduled as either prescription medicines (Schedule 4) or pharmacist‑only medicines (Schedule 3). The different schedule depends on specific criteria around safety, potential for misuse, and where it can be purchased, all specified in the product's Australian Register of Therapeutic Goods (ARTG) entry.
Like all medicines, products containing melatonin can cause adverse effects that clinicians and pharmacists should let their patients know about. These risks are significantly heightened if patients use unapproved melatonin purchased from overseas or online sources or compounded, where quality, potency, and safety cannot be assured.
In September 2025, the Therapeutic Goods Administration (TGA) issued a public safety alert after TGA laboratory testing revealed significant dose inconsistencies in unapproved melatonin products bought from overseas websites. Some products contained up to 400% more melatonin, while others contained less than stated or none. These variations pose serious risks, including overdose, hospitalisation, and adverse reactions, particularly in children.
Melatonin products presented as gummies or lolly-like formulations pose a significant risk of accidental overdose in children due to their appealing appearance and ease of consumption.
Symptoms of melatonin toxicity in children can include:
- Extreme sleepiness
- Vomiting
- Slurred speech
International reports have linked melatonin overdose to several child fatalities in the United States, underscoring the seriousness of this issue.
There is a growing number of Australians who are buying melatonin online because of the perceived cost benefits, perceived ease of availability and driven by associated misinformation that downplays the risks.
Unapproved melatonin products purchased from unverified sources are not identical to the approved products. These unapproved products have not been assessed by the TGA for quality, safety or efficacy.
Your patients should be advised to exercise extreme caution when purchasing medicines from unknown websites, as these medicines:
- may contain undisclosed and potentially harmful ingredients
- may not meet the same standards of quality, safety and efficacy as those approved by us for supply in Australia.
Clinicians and pharmacists play a key role in identifying and managing the risks associated with unapproved melatonin products.
Clinicians may prescribe prescription‑only melatonin to patients under their care when clinically appropriate, ensuring the dose, formulation, and duration are consistent with approved indications and directions for use.
Melatonin, in specified formulations and doses, is also available as a pharmacist‑only medicine for the short‑term treatment of insomnia in adults aged 55 years and older, and for jet lag in adults aged 18 years and older.
Clinicians and pharmacist can help by:
- advising patients not to purchase melatonin from unverified online sources. Patients should be advised to only purchase melatonin from an Australian-based pharmacy
- reporting adverse events involving any medicines, including unapproved products, via the TGA reporting portal - external site. These reports assist the TGA in identifying previously unknown side effects and other safety issues.
If a patient is using unapproved melatonin, strongly encourage them to stop immediately and safely dispose - external site of any remaining items at their local pharmacy.
The TGA has released a safety advisory on imported melatonin, including the results of our testing of 18 imported products.
