There is no EU-harmonised rule on melatonin in food supplements. It is governed nationally, and member states differ widely: some set a maximum dose, some set none, and some treat it as a medicine at any strength.
Lithuania sets a figure of 1 milligram per recommended daily dose for food supplements, above which a preparation is treated as a medicine and must be registered as one. The food and veterinary service stated this in July 2018, giving European Commission recommendations as its basis.
It is an agency position rather than a national legal act. It does not appear in the hygiene norm governing food supplements, in the notification order, or in any health ministry order we could locate, and the agency's original page no longer resolves following a website migration. The figure is nonetheless applied consistently by the Lithuanian market.
The boundary is visible from both sides. Melatonin food supplements at 1 milligram are openly sold through the main Lithuanian pharmacy chains in both oral spray and capsule form, including from a domestic manufacturer. Above the line, the medicines register carries melatonin as a registered medicine at 2, 3 and 5 milligrams. Nothing above 1 milligram appears on a Lithuanian pharmacy site as a food supplement.
