There is no EU-harmonised rule for melatonin. It sits outside the cannabinoid framework entirely and is governed nationally, member state by member state - limits range from 0.3 mg in Belgium to 2 mg in Spain, with several countries setting none at all. The one EU-level figure is the authorised health claim in Regulation (EU) 432/2012, which is conditional on 1 mg per quantified portion.
We identified no Cypriot national maximum for melatonin and no Cypriot decision reclassifying it as a medicine. Cyprus runs food supplements through a notification and licensing regime administered by the Ministry of Health's Public Health Services, under which a product already lawfully distributed as a food supplement in another EU member state ordinarily requires notification rather than a full licence. We found no national list of restricted other substances carrying maximum levels.
Cypriot retail practice matches that reading. Melatonin is stocked by Cypriot pharmacies and supplement retailers as an ordinary food supplement at 1 mg and at several multiples of it, sold without prescription.