There is no EU-harmonised rule on melatonin in food supplements. It is governed nationally, and member states have taken very different views. What is harmonised is the health claim: Regulation (EU) No 432/2012 authorises the statement that melatonin contributes to the reduction of time taken to fall asleep, and conditions it on the food containing exactly 1 mg of melatonin per quantified portion.

Estonia has set no maximum and applies no blanket classification. The Estonian regulation on the composition and quality of food supplements, in force since 13 December 2014 and still in force today, contains no melatonin provision of any kind: it regulates vitamins and minerals by reference to the EU food supplements directive and sets no maxima for other substances at all.

Classification is therefore case by case under the Medicines Act, through the State Agency of Medicines' determination procedure. No Estonian decision classifying a melatonin food supplement as a medicine was found.

The market shows where the line sits in practice. Estonian pharmacy chains sell melatonin food supplements at 1 mg and 1.95 mg per daily dose, in both oral spray and capsule form, while the melatonin products registered as medicines start at 3 mg with a jet-lag indication.

One separate Estonian rule is worth noting because it applies to medicines rather than to supplements: medicinal products may be sent to or from Estonia only between private individuals, which places any company-to-consumer shipment of a product classified as a medicine outside the permitted channel.