Melatonin: a timing signal, not a sleeping pill

Most fighters who use melatonin use it as a sedative. They take it because they cannot sleep, at the hour they want to sleep, in the dose that seems reasonable.

All three of those are usually wrong, and the reason is that melatonin does not do what people think it does.

It is not a sleeping pill

Melatonin is a hormone the body releases in response to darkness. Its job is not to switch you off. Its job is to tell every tissue in the body what time it is.

Researchers call it a chronobiotic: something that moves the timing of your internal clock rather than something that sedates you. The sleepiness people notice is downstream of that signal, not the mechanism.

Which explains the two things fighters report most often. That it does not really work when taken for ordinary insomnia. And that it worked spectacularly on one trip and did nothing on another.

Both follow directly from what it actually is.

Where the evidence is strong

Jet lag, and specifically jet lag, is where this compound earns its reputation.

A Cochrane review pooled 10 randomised trials of travellers crossing five or more time zones. Nine of the 10 found melatonin superior to placebo, and the authors described it as remarkably effective at preventing or reducing jet lag.

The American Academy of Sleep Medicine gave it their highest recommendation category for jet lag disorder.

That is a firmer evidence base than most things discussed on this site.

And where it is not

Broaden the question to sleep generally and the picture weakens considerably.

A systematic review of 35 randomised trials, most of them high quality, graded the recommendations. For preventing phase shifts from jet lag, for insomnia, and for initiating sleep, all three came out as weak recommendations rather than strong ones.

The dose people get wrong

Half a milligram is about as effective as five.

That comes out of the same jet lag literature and holds consistently: the larger dose does not shift the clock further, it just produces more grogginess the following morning.

Most products on a shelf contain three, five or 10 milligrams. Some contain considerably more. The market sells it as a sedative, and sedatives are dosed upward, so what is on sale reflects what buyers expect rather than what works.

For a fighter, next-morning grogginess lands on a weigh-in, a warm-up or a technical session, which makes it far more than a minor complaint.

Timing matters more than dose

This is the part almost nobody gets right, and getting it wrong is not neutral.

Melatonin taken at the wrong point in your own cycle shifts the clock in the wrong direction and can make the jet lag worse than doing nothing.

Which is why there is no timing table on this page. The correct hour depends on how many zones you crossed, which direction you flew, and where your own clock currently sits. A protocol that works flying west is close to the opposite of the one that works flying east, and getting the direction wrong is the common failure.

If you are going to use it, work the timing out properly for your specific journey, with somebody qualified or with a tool built for it. The dose is trivial to get right. The hour is not.

The direction of travel is where that reasoning starts.

The problem that makes all of this theoretical

Everything above assumes the tub contains what the label says.

An analysis of 31 melatonin products found actual content ranging from 83 percent below the labelled amount to 478 percent above it, with significant variation between batches of the same product.

Read that against the previous section. The whole argument for low dosing collapses if the product marked 0.5 mg is delivering something else entirely, and you have no way of knowing which one you bought.

Melatonin is sold as a dietary supplement in most markets, which means it is not regulated to pharmaceutical standards. It carries the same category risk as everything else here: what is in the container is not guaranteed to match the label, and undeclared contamination cannot be ruled out.

The anti-doping position

Melatonin is not on the Prohibited List. Not prohibited in or out of competition, and no therapeutic use exemption is needed.

That answers the question people ask and not the one that matters.

The risk here comes from the category more than the substance. A minimally regulated supplement, bought from a shelf, entering a tested athlete's system, is the same exposure as any other supplement and deserves the same process: batch-tested product, batch confirmed on a certifier's register, logged with everything else that enters the camp.

A fighter who would check his protein powder and not check his melatonin has not understood what the check is for.

What I would actually do

On the second row: late caffeine, hard evening sessions, a cut that has gone too deep, or the ordinary anxiety of fight week. Those are the usual causes, and reaching for melatonin is often a way of not addressing them. What actually moves sleep is covered separately.

Two medical notes, because they are the ones that matter. Melatonin can interact with warfarin, and caution is advised in epilepsy.

Anybody on regular medication should raise it with a doctor rather than assume that a supplement is automatically compatible.