Melatonin is a hormone made by the pineal gland in your brain. Your body releases it as it gets dark, and levels peak around 2am to 4am. Its main job is timing: it tells your body clock that it's night. It isn't a sedative, which is why melatonin supplements help most with body-clock problems such as jet lag, and much less with everyday insomnia.

Short-term use in healthy adults is generally considered low-risk. Reported side effects include headache, dizziness, nausea, vivid dreams and next-day grogginess. Long-term safety is less well studied. Melatonin can interact with blood thinners, sedatives, diabetes medicines, immunosuppressants and some antidepressants such as fluvoxamine. It isn't recommended in pregnancy or breastfeeding. Check with your doctor before using it, especially for more than a few weeks.

10 mg is about 33 times the 0.3 mg dose that restored normal night-time melatonin levels in research. There's no good evidence that higher doses work better for sleep, and the Cochrane review on jet lag found no added benefit above 5 mg. Higher doses are more likely to keep melatonin raised into the next day. Speak to a doctor before taking 10 mg or more regularly.

These doses are far above anything used for sleep in mainstream research, and far above what your body makes. Don't take doses like these unless a doctor has prescribed them for a specific medical reason.

Research suggests lower is often better. Around 0.3 to 0.5 mg recreates natural night-time levels, and for jet lag, doses from 0.5 to 5 mg worked about equally well. But the more useful question comes first: do you actually need melatonin? If your body clock isn't the problem, no dose is the right dose.

No. Sleeping pills such as zolpidem act as sedatives on the brain. Melatonin is a hormone that acts as a timing signal. That's why it doesn't "knock you out", and why it does little when the reason you're awake is stress, tension, hot flashes or a 3am wake-up.

Melatonin isn't addictive in the way sedative sleeping pills can be. But taking it every night can hide the real reason you aren't sleeping, and there's limited data on years of nightly use. If you've needed something every night for more than a few weeks, it's worth finding the cause with a doctor.

Current evidence suggests short-term use doesn't shut down your own production, and natural levels continue when you stop. The bigger concern is different: a supplement can cover up the real reason you're not sleeping, while that reason goes unaddressed.

Not without a paediatrician's advice. The American Academy of Sleep Medicine advises parents to speak to a doctor before giving melatonin to children. In the US, reported melatonin ingestions in children rose 530% between 2012 and 2021, mostly accidental, in children under 6. Never give melatonin to an infant or newborn unless a doctor has prescribed it.

It isn't recommended without your doctor's advice, because there isn't enough safety data. Melatonin crosses the placenta and plays a role in the baby's developing body clock. If you're pregnant or breastfeeding and struggling to sleep, talk to your obstetrician before taking any sleep supplement.

In the Cochrane review, melatonin worked best taken close to your target bedtime at your destination (roughly 10pm to midnight local time) for a few days, especially after flying east across five or more time zones. Taken at the wrong time of day, it can delay adjustment, so ask a pharmacist or doctor about timing for your trip.

Magnesium and melatonin are often combined and have no well-known interaction. But adding magnesium doesn't make melatonin necessary. If physical tension or restlessness is what keeps you up, magnesium on its own may be what you were really after, as in The Upside's Body Release or magnesium with vitamin B6.

Some products combine them. Ashwagandha works on the stress response, which is a far more common cause of poor sleep than low melatonin. If stress is your issue, ashwagandha without the hormone, such as the KSM-66 in The Upside's Clear Days, may make more sense. Check with your doctor if you take thyroid medicine, sedatives or immunosuppressants, or are pregnant.

Only if your doctor has told you to. Both can cause drowsiness, and combining sleep medicines can increase next-day impairment. Never add melatonin to a prescription sleep medicine without checking first.

Yes. Melatonin tablets, gummies and strips are widely sold online and at chemists in India without a prescription. In the UK, melatonin is a prescription-only medicine, and in Australia it's only available from a pharmacist or with a prescription. Being easy to buy isn't the same as being right for you.

Only modestly. On average, it helps people fall asleep about 7 minutes faster, and the American Academy of Sleep Medicine suggests doctors don't use it for chronic insomnia in adults. Insomnia usually has a cause, such as stress, anxiety, pain, hormones, habits or another sleep disorder, and treating that cause works better.

Not much. Melatonin influences when you sleep more than how deeply you sleep. If you wake up unrefreshed, ingredients studied for sleep quality, such as 3g of glycine, are a better match. In sleep lab studies, glycine shortened the time it took to reach deep, slow-wave sleep.

Start with light: morning daylight, dim evenings and a steady wake-up time support your own melatonin. For non-hormonal supplements, the best choice depends on why you're not sleeping: glycine for deep sleep, L-theanine and passionflower for a busy mind, magnesium for tension, and ashwagandha or saffron for stress. Find your match above.

Almost all supplement melatonin is synthetic and chemically identical to the hormone your body makes. "Natural" melatonin extracted from animal glands is rarely sold today because of contamination risks. The natural melatonin that matters most is the kind your own body makes every evening.

Topical melatonin applied to the scalp has been studied in small trials for hair thinning. That's a different use from sleep, and melatonin tablets taken for sleep aren't a hair treatment. Speak to a dermatologist about hair loss.