Melatonin works for jet lag mainly because of when it is taken, not how much. A Cochrane review of ten randomised trials found it reduced jet lag for flights crossing five or more time zones, and that taking it at the wrong hour can delay adjustment instead of speeding it up [1].
For travellers flying out of India, the direction that causes the most trouble is usually the way home.
This information is for educational purposes only. It is not medical advice. Talk to a healthcare professional before starting any new supplement.
Why Jet Lag Hits Indian Travellers Hardest on the Return Leg
Most jet lag advice online is written from a North American or British desk. In that world, "flying east" means heading to Europe or Asia, and that is treated as the hard direction.
Flip the map to Delhi or Mumbai and the picture inverts.
Flights out of India heading for New York, London or San Francisco run westward. The day gets longer. The body clock has to drift later, which it is naturally inclined to do anyway. The CDC Yellow Book puts the average adaptation rate at about 1.5 hours per day westward, against roughly 1 hour per day eastward [2].
Then the trip ends, and the traveller flies home. That leg is eastward. The day shortens. The body clock has to jump forward, which is the harder move for almost everyone.
Call it the return leg problem: Indian travellers plan carefully for the outbound flight, feel reasonably fine on arrival, and then get flattened during their first week back at work in India.
What Melatonin Actually Does to Your Body Clock
Melatonin is a hormone made in the pineal gland, a small structure in the brain. Its production is controlled by light signals that the retina sends along the retinohypothalamic tract into the suprachiasmatic nucleus, the region of the hypothalamus that runs the body's daily timing [3].
Under a normal schedule, melatonin starts rising about two hours before habitual bedtime and peaks somewhere around 3 to 4 a.m. [2].
Here is the part that gets lost in most travel articles. Supplemental melatonin is not primarily a sedative. It is a timing signal.
Taken when the internal clock thinks it is early evening, it shifts the clock earlier, which is what an eastward traveller needs. Taken when the internal clock thinks it is morning, it shifts the clock later, which is what a westward traveller needs [2].
That single distinction explains why the same capsule helps one person and does nothing for another.
Melatonin and Jet Lag: What the Research Actually Found
The strongest evidence comes from a Cochrane systematic review by Herxheimer and Petrie, covering ten randomised trials in airline passengers, airline staff and military personnel [1].
Eight of the ten trials found that melatonin taken close to target bedtime at the destination, roughly 10 p.m. to midnight local time, reduced jet lag from flights crossing five or more time zones [1].
A few specifics from that review are worth holding onto.
Daily doses between 0.5 mg and 5 mg were similarly effective, though participants fell asleep faster on 5 mg than on 0.5 mg. Doses above 5 mg were no more effective. A 2 mg slow-release form performed relatively poorly, which suggests a short sharp peak works better than a long low one [1].
The reviewers estimated a number needed to treat of 2. In plain terms, roughly one traveller in two got a benefit [1].
The benefit grew with the number of time zones crossed, and was smaller for westward flights [1].
There is a counterweight worth stating plainly. The NHS does not recommend melatonin tablets for jet lag, on the grounds that there is not enough evidence they work [4].
Two credible bodies are reading the same small set of trials and applying different thresholds for what counts as proof. A reader deciding what to do deserves both halves of that picture.
Eastward vs Westward Travel From India: Which Trips Are Which
Direction is not about the compass heading of the aircraft. It is about whether local clocks at the destination read earlier or later than at home.
India runs on UTC+5:30. Working outward from there:
Westward from India (day gets longer, adaptation is easier):
- India to London, roughly 4.5 to 5.5 hours behind depending on British Summer Time
- India to New York, roughly 9.5 to 10.5 hours behind
- India to San Francisco, roughly 12.5 to 13.5 hours behind
- India to Dubai, 1.5 hours behind
Eastward from India (day gets shorter, adaptation is harder):
- India to Singapore or Kuala Lumpur, 2.5 hours ahead
- India to Tokyo, 3.5 hours ahead
- India to Sydney, roughly 4.5 to 5.5 hours ahead depending on daylight saving
- Every return flight home out of the Americas or Europe, which is the leg most travellers forget to plan for
Note the Cochrane threshold again. The review recommends melatonin for adult travellers crossing five or more time zones, particularly eastward, and says travellers crossing two to four zones can use it if needed [1].
By that standard, a Mumbai to Singapore hop sits below the line where melatonin has the clearest support. A Mumbai to New York round trip sits well above it, in both directions.
Why India's Half-Hour Offset Makes Zone Counting Confusing
India is one of a small set of countries running a half-hour offset against UTC. The time zone count for almost any Indian itinerary therefore lands on a fraction.
Delhi to London in winter is 5.5 zones. Delhi to Tokyo is 3.5. Delhi to New York in summer is 9.5.
Jet lag calculators and generic articles assume whole numbers, so travellers often round in whichever direction feels convenient and end up planning around the wrong figure.
The practical fix is to stop counting zones and start reading clocks. What time will it be at the destination when the flight lands, and what time will it be there when a normal night's sleep should begin? Those two numbers drive every decision that follows.
Timing Melatonin for Jet Lag: The Clock Beats the Dose
Cochrane's reviewers were blunt about the risk here. Taken at the wrong time, early in the day, melatonin is liable to cause sleepiness and delay adaptation to local time [1].
So it is possible to take melatonin for jet lag and end up more misaligned than if nothing had been taken at all.
The CDC Yellow Book adds two useful details. Doses of 0.5 to 1 mg are often sufficient to produce a circadian shift, and taking melatonin when the body's own melatonin is already high, roughly body-clock time between midnight and 5 a.m., is not as effective [2]. The same source advises against high-dose melatonin above 5 mg, because the excess can still be circulating at the wrong point in the next day [2].
For eastward travel, the CDC guidance describes melatonin taken before bedtime at the destination to support the natural evening rise [2].
For westward travel, the mechanism runs the other way, and light exposure tends to do more of the work.
None of this is a prescription. Timing that depends on the direction of travel, the number of zones crossed and an individual's own sleep pattern is exactly the kind of decision worth taking to a doctor before a long trip, especially a first attempt.
What Light Exposure Does That Melatonin Cannot
Melatonin nudges the clock. Light moves it.
Exposure to bright light in the morning, after the body's temperature low point, promotes a phase advance and shifts the system earlier. Evening light generally promotes a phase delay and shifts it later [2].
This is why the returning-to-India traveller has two levers, not one. Morning daylight in India after landing pushes the clock earlier, which is the direction that leg requires. Bright evening light at home works against it.
The American Academy of Sleep Medicine lists several standard treatments for jet lag disorder in frequent travellers. Timed melatonin is one. Timed light exposure is another. Sleep scheduling sits alongside them, and hypnotics or stimulants appear as options under medical supervision [2].
Melatonin is one item on that list. Anyone treating it as the whole plan is leaving the strongest tool, daylight, unused.
The CDC also notes practical basics that do not need a supplement at all: shifting sleep by an hour a day for two to three days before departure, timing meals and sleep to the destination zone during the flight, staying hydrated, limiting alcohol, and keeping daytime naps at the destination to 20 to 30 minutes [2]. The NHS gives broadly similar advice and adds that for trips of only two to three days, some travellers do better staying on home time entirely [4].
Melatonin Side Effects and Who Should Take Extra Care
Melatonin has a low rate of side effects, and the ones that do occur are usually mild: drowsiness, daytime sedation, nausea and headaches, more often at higher doses and with extended-release forms [3].
Its elimination half-life is short, typically one to two hours, though this varies with formulation [3]. Bioavailability is unpredictable, reported anywhere between 1% and 74% depending on formulation and dose [3].
Some groups warrant more caution than a travel article can settle.
Cochrane's review flagged case reports suggesting that people with epilepsy and patients taking warfarin may come to harm from melatonin [1]. Melatonin is metabolised largely by the liver enzyme CYP1A2, so strong inhibitors of that enzyme can raise exposure, and combining melatonin with benzodiazepines or other sedatives may cause excessive sedation [3]. Clinicians are advised to steer pregnant and breastfeeding women away from it, on grounds of insufficient safety evidence rather than known harm [3].
Anyone in those categories, or on regular medication of any kind, should be having this conversation with a doctor rather than a search engine. The wider question of how supplements interact with each other and with prescription medicine is covered in the complete guide to supplements and nutraceuticals for Indians.
What to Check on a Melatonin Label Before a Long Flight
This is where the topic stops being about biology and starts being about manufacturing.
Erland and Saxena analysed 31 melatonin products across 16 brands. Actual melatonin content ran as low as 83% under the labelled amount and as high as 478% over it. More than 70% of products missed their label claim by more than 10%, and batch-to-batch variation within a single product reached 465%. Serotonin, a far more tightly controlled compound, turned up in 26% of the samples tested [5].
The CDC Yellow Book makes the same point from a regulatory angle: because melatonin is not regulated by the FDA as a drug, the amount in the bottle may differ from what is printed on the label [2].
That finding reframes the whole timing discussion. Careful planning around a stated milligram figure is worth very little if the figure is fiction.
So the useful questions before buying are about the manufacturer, not the molecule:
- Does the brand publish third-party test results for the batch, not just a generic quality claim?
- Is the full ingredient list disclosed, with no proprietary blends hiding quantities?
- Is the form stated plainly as immediate-release or extended-release, given that the Cochrane data favoured a sharper peak [1]?
- Are the other actives in a combination product listed at their actual amounts?
The Oak Age's Sleep Support formula combines melatonin with L-theanine and L-tryptophan, with each ingredient quantity stated on the label and every batch tested for purity. Readers weighing a combination product against a single-ingredient one may find the breakdowns in the guides to the best L-theanine supplement in India and the best L-tryptophan supplement for sleep quality useful for understanding what each part contributes.
Building a Jet Lag Plan for an Indian Itinerary
A workable plan has four moving parts, and melatonin is only one of them.
Start with the direction. Outbound to Europe or the Americas is westward and generally the gentler leg. The flight home to India is eastward and is where most of the disruption shows up. Plan the return with more care than the departure, not less.
Count the clocks, not the zones. Work out what local time it will be at the destination when a normal night's sleep should start. That single number anchors everything.
Book the daylight. Morning light after landing in India helps pull the clock earlier. Evening light works against it. This lever costs nothing and, on the evidence, does at least as much work as any capsule [2].
Then decide about melatonin, with a doctor. The Cochrane review supports it most clearly for adults crossing five or more zones, particularly eastward, and especially for people who have had jet lag before [1]. Below that threshold the case is weaker. Timing is the variable that decides whether it helps or hurts [1].
For frequent flyers, one more thing is worth saying plainly. Repeated circadian disruption is not just an inconvenience at the destination; it is a recurring stressor on sleep quality over years. The groundwork covered in the complete guide to sleep and recovery for Indians matters more for that group than any single-trip tactic.
Checking what is actually in the bottle
The label questions in this guide, applied to The Oak Age's own sleep formula: stated ingredient quantities, no proprietary blends, third-party batch testing.
See Sleep SupportReaders comparing Indian sleep products against the criteria above can also work through the guide to choosing a melatonin supplement in India, or look at how The Oak Age documents ingredient quantities and batch testing across its full supplement range.
Frequently Asked Questions
Does melatonin work for jet lag on short flights out of India, say to Dubai or Singapore?
Those routes cross 1.5 and 2.5 time zones respectively. The Cochrane review recommends melatonin for adult travellers crossing five or more zones, and says those crossing two to four zones can use it if needed [1]. Short-hop routes sit at or below the weaker end of that evidence, and sleep scheduling plus daylight usually handles them.
Is jet lag worse flying to India or flying out of India?
For destinations in Europe and the Americas, the return flight to India is the eastward leg, and eastward adaptation is slower. The CDC Yellow Book puts average adaptation at about 1 hour per day eastward against 1.5 hours per day westward [2].
Can melatonin make jet lag worse?
Yes, if the timing is wrong. Cochrane's reviewers noted that melatonin taken early in the day can cause sleepiness and delay adaptation to local time [1]. This is the main reason to plan the timing before departure rather than improvising on arrival.
Why do the NHS and Cochrane disagree about melatonin for jet lag?
The Cochrane review concluded melatonin is effective for jet lag across five or more time zones [1], while the NHS says melatonin tablets are not recommended for jet lag because there is not enough evidence they work [4]. The trial base is small and the two bodies apply different evidence thresholds to it.
Does it matter whether the melatonin is immediate-release or extended-release?
The Cochrane review found a 2 mg slow-release formulation relatively ineffective and concluded that a short-lived higher peak concentration appears to work better for jet lag [1]. The formulation is worth checking on the label.
How reliable is the milligram figure printed on a melatonin bottle?
Less reliable than most buyers assume. Testing of 31 products found melatonin content between 83% below and 478% above the labelled amount, with over 70% of products outside a 10% margin of their claim [5]. Third-party batch testing is the practical check.
References
1. Herxheimer, Andrew, and Keith J. Petrie. "Melatonin for the Prevention and Treatment of Jet Lag." Cochrane Database of Systematic Reviews, no. 2, 22 Apr. 2002, art. no. CD001520, www.cochrane.org/evidence/CD001520_melatonin-prevention-and-treatment-jet-lag.
2. Riedy, Samantha M., and Scott G. Williams. "Jet Lag Disorder." CDC Yellow Book: Health Information for International Travel, 2026 ed., Centers for Disease Control and Prevention, 23 Apr. 2025, www.cdc.gov/yellow-book/hcp/travel-air-sea/jet-lag-disorder.html.
3. Savage, Rosemary A., et al. "Melatonin." StatPearls, StatPearls Publishing, National Center for Biotechnology Information, 9 Feb. 2024, www.ncbi.nlm.nih.gov/books/NBK534823/.
4. "Jet Lag." NHS, National Health Service, 31 May 2023, www.nhs.uk/conditions/jet-lag/.
5. Erland, Lauren A. E., and Praveen K. Saxena. "Melatonin Natural Health Products and Supplements: Presence of Serotonin and Significant Variability of Melatonin Content." Journal of Clinical Sleep Medicine, vol. 13, no. 2, 15 Feb. 2017, pp. 275-281, pubmed.ncbi.nlm.nih.gov/27855744/.
The information on this page is for educational purposes only. It is not intended to diagnose, treat, cure, or prevent any disease. Consult a healthcare professional before making changes to your supplement routine. Statements on this page have not been evaluated by the Food Safety and Standards Authority of India (FSSAI).
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