A precision-dosing and sleep-tracking guide for melatonin, the most over-dosed sleep aid on the shelf.
At a glance
Best for
Melatonin is a hormone produced by the pineal gland that signals "biological night" to the rest of the body. It is sold over the counter in many countries (and is prescription-only in much of the EU and UK), often at doses ten to twenty times higher than what the pineal gland actually produces. That mismatch is the single most useful thing to understand about it.
Melatonin is primarily a circadian signal, not a sedative. Its strongest evidence is for shifting sleep timing (jet lag, shift work, delayed sleep phase) rather than for forcing sleep at a normal bedtime. It also has antioxidant properties at higher doses, though clinical relevance varies by context.
Two distinct use cases, two different shapes:
The common mistake is taking 5 to 10 mg at bedtime, which floods receptors and often produces grogginess the next morning without improving sleep architecture.
Bloodwork is rarely needed for melatonin specifically. If you are using it long term and have unexplained fatigue, a thyroid panel and morning cortisol are reasonable.
For jet lag eastward, small evening doses for a few days are well supported. For shift work, modest benefit. For "I want to sleep better tonight," melatonin is usually less effective than people expect, and the dose-response curve is not linear: more is not better, and is often worse.
In Peptide IA, log dose and time in the evening entry, then sleep latency and morning grogginess the next day. The pattern usually appears within two weeks: most people find a lower dose works at least as well as their starting dose.
Melatonin is a useful circadian tool used precisely, and a sleep-quality liability used carelessly. The dose almost always wants to be smaller than you think.
Peptide IA is an educational and self-tracking tool. Nothing in this post is medical advice. Doses mentioned reflect what is commonly reported in research literature — they are not recommendations. Always consult a qualified physician before starting, changing, or stopping any protocol.