Melatonin: 1 mg, and not at just any hour

In the whole EU register, melatonin is the only substance carrying a claim directly tied to falling asleep. No plant, no mineral, no amino acid holds one — which is what makes the “sleep” aisle so talkative and so vague.

Two claims are authorised for it, reproduced below, each with its own condition of use.

This is the point most products miss. The sleep-onset claim is usable only if two conditions are met: the portion supplies at least 1 mg, and the “shortly before bedtime” instruction accompanies the product.

A product dosed at 0.3 mg cannot carry that claim, even though it does contain melatonin. A correctly dosed product silent on timing does not fully satisfy the condition either.

For jet lag the threshold drops to 0.5 mg, taken on the first day of travel and the following days on arrival.

The condition of use sets a minimum threshold for communicating. It does not describe a rising dose-response relationship, and reading it that way would be wrong.

Melatonin is a hormone whose natural secretion is on the order of a tenth of a milligram. The high doses found outside Europe belong to a different regulatory framework, where it is sometimes sold as a medicine. In Belgium, a melatonin-based supplement remains subject to dose limits set by national regulation.

The authorised claim concerns TIME TAKEN TO FALL ASLEEP — the interval between going to bed and falling asleep. It concerns neither total sleep duration, nor sleep quality, nor night-time waking.

That distinction is useful when choosing: for someone who falls asleep quickly but wakes at three in the morning, melatonin does not address the problem, and no European claim pretends otherwise.