Melatonin Supplements: Jet Lag and Sleep Evidence, Indian Rules and Safety

Melatonin is a hormone made mainly by the pineal gland in the brain, and it helps set the timing of sleep and waking. The tablets, gummies and sprays sold as sleep aids contain a synthetic copy. In India FSSAI lists it as a nutraceutical ingredient with a permitted range of 2 to 10 mg a day. The evidence is uneven: good for jet lag after long flights, modest for falling asleep, and thin on long-term safety. This entry covers the supplement and sits in the supplements section of the handbook; the hormone your own body makes is a separate subject.

What is melatonin and what does a supplement do?

Melatonin is a signal, not a sedative in the usual sense. The body releases it according to its internal clock, and the Cochrane review of jet lag describes it as playing a central part in regulating bodily rhythms. A supplement taken at the right hour can nudge that clock towards a new schedule, which is why the best evidence concerns travel across time zones. Taken to force sleep on demand, the effect is much smaller. Researchers also note what it lacks: a 2013 meta-analysis describes little potential for dependence and typically no hangover the next morning.

Because the clock is the target, timing matters as much as the amount. The same review warns that melatonin taken at the wrong time, early in the day, is liable to cause sleepiness and to delay adaptation to local time. A tablet swallowed at random hours works against the thing it is meant to help.

The Indian position: no ICMR-NIN requirement, an FSSAI range of 2 to 10 mg

ICMR-NIN sets no requirement for melatonin, because the body makes its own and it is not a nutrient. The Dietary Guidelines for Indians (2024) do not mention it as a supplement. What they say about sleep is behavioural: healthy sleeping patterns of 6 to 8 hours a day, less non-essential screen time, and moderation in tea and coffee because of their caffeine. The caffeine entry sets out how much each cup carries.

FSSAI's health supplement and nutraceutical regulations list melatonin in Schedule VI, Part A, with a permitted range of 2 to 10 mg a day, maximum. The entry carries no purity criterion and, unlike several neighbouring entries, no printed restriction for pregnancy, lactation or age. That silence is not a clearance. The same regulations do not apply to infants under 24 months, and say products for children aged 2 to 5 years shall be given only under medical advice.

Does melatonin work for jet lag?

Yes, and this is the strongest evidence it has. A Cochrane review found ten randomised trials in airline passengers, airline staff and military personnel. Nine of the ten showed that melatonin taken close to the target bedtime at the destination, between 10 pm and midnight, decreased jet lag from flights crossing five or more time zones. The reviewers estimated a number needed to treat of 2, meaning roughly one traveller in two benefited beyond placebo.

The detail is useful. Daily amounts between 0.5 and 5 mg were similarly effective, except that people fell asleep faster and slept better after 5 mg than after 0.5 mg, and amounts above 5 mg appeared no more effective. A 2 mg slow-release form did relatively poorly. The benefit was greater the more time zones were crossed and smaller for westward flights. The review dates from 2002, and its authors asked for systematic study of melatonin's toxicology and for routine quality control of products.

Does melatonin help you fall asleep faster?

A little. A 2013 meta-analysis pooled 19 placebo-controlled trials with 1,683 adults and children who had primary sleep disorders. Melatonin shortened the time taken to fall asleep by 7.06 minutes on average and lengthened total sleep by 8.25 minutes, with a small improvement in rated sleep quality. The authors themselves call the effects modest. They point out that earlier analyses of benzodiazepine sleeping pills found gains of 10.0 to 19.6 minutes in falling asleep. Part of the study's funding came from fellowships sponsored by a pharmaceutical company.

Clinical guidance is cooler still. The American Academy of Sleep Medicine's 2017 guideline on medicines for chronic insomnia suggests that clinicians not use melatonin for either sleep onset or sleep maintenance insomnia in adults. It grades that as a weak recommendation, which under its method reflects limited certainty in the published data, not proof that melatonin does nothing. Persistent insomnia is a medical complaint with many possible causes, and it belongs with a doctor, not with a supplement shelf.

How do the trial amounts compare with the Indian range?

They overlap only partly. The jet lag trials used 0.5 to 5 mg and found nothing gained above 5 mg, while FSSAI's schedule runs from 2 to 10 mg a day. The upper half of the Indian range therefore sits above the amount at which the jet lag benefit levelled off, and the lowest amounts that worked in trials sit below the range's floor. None of these figures is a recommendation; they describe what researchers gave and what a manufacturer may sell.

How reliable is the amount printed on the label?

Less reliable than you would hope, on the one detailed study available. Researchers in Canada bought 31 melatonin supplements from local shops and pharmacies and measured the contents. The actual melatonin ranged from 83 per cent below to 478 per cent above the label, more than 71 per cent of products missed their label by over 10 per cent, and different lots of the same product varied by as much as 465 per cent. One chewable tablet labelled 1.5 mg held almost 9 mg. Serotonin, a controlled substance, turned up in eight products.

No comparable analysis of Indian products was found for this entry, so those figures cannot be assumed to hold here, in either direction. What they show is that a nutraceutical does not pass through the batch testing a medicine does, and that the number on the strip is a claim. The Cochrane reviewers made the same point about quality control in 2002.

A worked example: a traveller from Bengaluru

This case is an illustration, not a real person. Take a healthy 38-year-old woman in Bengaluru, on no medicines and not pregnant, who is flying to Toronto for ten days of work and back. Both legs cross well over five time zones. She has bought a strip of 3 mg tablets and wants to know whether the research applies to her.

Common mistakes and myths about melatonin

The usual mistakes follow from treating melatonin as a sleeping pill. People take it nightly for months, although most trials lasted four weeks or less. People take a second tablet at 2 am when the first seems not to work, which is the wrong-time use the jet lag review warns about. People assume a bigger number on the pack is stronger sleep, and they keep late coffee, bright screens and irregular hours unchanged. Questions about food at bedtime, such as whether milk at night helps, are handled on their own pages; an evening cup of chai works in the opposite direction.

Side effects, safety and when to see a doctor

Short-term use looks well tolerated in adults. A 2019 systematic review of 37 randomised trials found few adverse events, mostly mild: daytime sleepiness in 1.66 per cent of participants, headache in 0.74 per cent, dizziness in 0.74 per cent and a fall in body temperature in 0.62 per cent. Agitation, mood swings, nightmares and palpitations were reported rarely. The reviewers judged only eight of the trials good on risk of bias, and concluded that the scarcity of long-term trials limits what can be said about continuous use.

A second 2019 review of 50 controlled studies found that 24 reported at least one statistically significant adverse event, mostly fatigue, mood or slowed mental and physical performance. A few studies noted changes in blood pressure, heart rate, glucose metabolism and reproductive hormones, apparently depending on dose, timing and interaction with blood pressure medicines. Do not drive or operate machinery after taking melatonin.

Ask a doctor before using melatonin if you are pregnant, trying to conceive or breastfeeding, since none of the reviews read for this entry offers safety data for those groups. Ask first if you have epilepsy or take warfarin, the two groups the Cochrane review flagged from case reports, or if you have asthma, diabetes, a heart rhythm problem or treated blood pressure. Ask first if you take sedatives, sleeping pills, antidepressants or any regular medicine, and do not stop a prescribed medicine in favour of melatonin. Sleep trouble that lasts beyond a few weeks, loud snoring with daytime sleepiness, or low mood needs a medical assessment.

Why are children a special concern?

Because the evidence in children is thin and accidental swallowing is common where melatonin is sold freely. The 2013 meta-analysis could not analyse children separately for lack of trials, and the 2019 safety review recorded concern about exposure in children before adolescence. In the United States, poison centres logged 260,435 ingestions by people aged 19 or under between 2012 and 2021, a 530 per cent rise in the annual number, with the growth in serious outcomes driven mainly by unintentional swallowing in children aged 5 or under. Five children needed mechanical ventilation and two died. Melatonin for a child is a paediatrician's decision, and the pack belongs out of reach.

NNWA courses that cover sleep aids and supplements

Melatonin appears as a case study in the Dietary Supplements and Nutraceuticals course, and sleep as part of lifestyle in the Diploma in Nutrition. NNWA is a private skill academy in Kolkata that teaches online in English and in Hindi. Its courses equip people to coach healthy adults and to send medical questions, persistent insomnia among them, to a doctor. They are not degrees and do not qualify anyone as a dietitian.