Melatonin

non-nutrient/non-botanical

Best before bedTake with food

What is it

Melatonin is a hormone produced naturally by the pineal gland in response to darkness that signals the body's transition to nighttime and helps regulate the sleep-wake cycle. It is also available as a dietary supplement, commonly used as a short-term sleep aid and for circadian rhythm adjustment.

How it works

Endogenous melatonin synthesis begins in the pineal gland from the amino acid tryptophan, which is converted first to serotonin and then enzymatically transformed into melatonin. Production rises in the evening as light exposure diminishes and peaks during the middle of the night, falling sharply by morning. This nocturnal surge acts as the body's chemical signal of biological night. Melatonin exerts its effects primarily through two G-protein-coupled receptors, MT1 and MT2, which are concentrated in the suprachiasmatic nucleus of the hypothalamus, the body's master circadian clock. Activation of these receptors promotes sleep onset, lowers core body temperature, and shifts the timing of the internal clock. Supplemental melatonin works best as a chronobiotic, nudging the timing of the circadian rhythm, rather than as a sedative. Research suggests melatonin is particularly useful for sleep onset latency in people with delayed sleep phase syndrome, for jet lag, and for shift workers. Its effect on staying asleep is generally smaller than its effect on falling asleep.

Evidence for 6 uses

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

Jet lag

Grade B

Good evidence

Multiple randomized trials and reviews indicate melatonin can reduce the symptoms of jet lag, particularly when crossing five or more time zones eastward. Effects include faster sleep onset, improved sleep quality, and reduced daytime fatigue at the new location. Doses of 0.5 to 5 mg taken at the destination's bedtime for several nights are commonly studied.

Sleep onset insomnia

Grade B

Good evidence

Research indicates melatonin modestly reduces the time it takes to fall asleep in adults with primary insomnia, with average reductions of around 7 to 12 minutes in meta-analyses. The effect is more pronounced in older adults whose endogenous melatonin production has declined. Effects on total sleep time and sleep quality are smaller.

Delayed sleep phase syndrome

Grade B

Good evidence

Low-dose melatonin taken in the early evening can advance the circadian phase in people whose natural sleep onset is delayed, helping them fall asleep at conventional bedtimes. This use requires precise timing several hours before the desired sleep time and works best paired with morning light exposure.

Pediatric sleep disorders (ADHD, ASD)

Grade B

Good evidence

Several trials show melatonin reduces sleep onset latency in children with ADHD and autism spectrum disorder who have comorbid sleep difficulties. Pediatric use should be supervised by a clinician, and behavioral sleep interventions should be tried first.

Shift work sleep disorder

Grade C

Moderate evidence

Studies suggest melatonin may improve daytime sleep duration and quality for shift workers, particularly those on rotating or night shifts. Evidence is mixed and dependent on shift schedule, dose, and timing. Combining melatonin with strategic light exposure tends to produce better outcomes than melatonin alone.

Antioxidant effects

Grade C

Moderate evidence

Mechanistic and small clinical studies suggest melatonin acts as a free-radical scavenger and may have neuroprotective properties. Clinical relevance for chronic disease outcomes is unclear and not established for routine supplementation.

3 commercial forms

Immediate-release

Rapid onset within 30 to 60 minutes; short half-life of about 40 minutes.

Best suited for difficulty falling asleep. Available in tablets, capsules, sublingual, and gummies.

Extended-release

Slower release designed to mimic the body's natural overnight melatonin pattern.

Often used for sleep maintenance issues, particularly in older adults. May reduce middle-of-the-night awakenings.

Sublingual / liquid

Absorbed through the oral mucosa, potentially faster onset than swallowed tablets.

Useful for rapid sleep onset and for people who prefer to avoid swallowing pills.

Dosage

There is no RDA for melatonin because the body produces it endogenously. Supplemental doses studied in research range widely, typically from 0.3 mg to 5 mg taken 30 to 60 minutes before bed. Low doses (0.3 to 1 mg) often match physiologic levels and may be sufficient for circadian shifts and sleep onset. Higher doses (3 to 10 mg) are commonly sold but are not necessarily more effective and may increase next-day grogginess. Extended-release formulations are designed to support sleep maintenance.

When and how to take it

WHEN: Take melatonin 30 to 60 minutes before your intended bedtime. For jet lag, take it at the destination's bedtime starting the night of travel. For delayed sleep phase, take low-dose melatonin (0.3 to 0.5 mg) in the early evening, several hours before the desired sleep time. HOW: With or without food, though taking it with a small snack may reduce nausea in sensitive individuals. Avoid bright light, especially blue light from screens, after taking melatonin to enhance its natural effect. Do not combine with alcohol or other sedatives. Start with the lowest effective dose.

Food sources

Food	Amount	%DV
Tart cherries (Montmorency)	1 cup	—
Pistachios	1 oz	—
Walnuts	1 oz	—
Eggs	2 large	—
Milk (especially nighttime-milked)	1 cup	—
Salmon	3 oz	—

Safety

Melatonin has a strong short-term safety profile in healthy adults. Common side effects include daytime drowsiness, headache, dizziness, nausea, and unusually vivid dreams. Long-term safety data are limited. There is no established Tolerable Upper Intake Level. Supplemental melatonin can lower body temperature and may transiently affect mood. Quality control concerns exist: independent testing has found that some melatonin products contain doses substantially different from label claims.

Who should be cautious

Pregnant and breastfeeding women should avoid melatonin due to limited safety data. People with autoimmune conditions should consult a clinician because melatonin can modulate immune function. Those taking sedatives, blood thinners, blood pressure medications, anticonvulsants, or immunosuppressants should seek medical guidance. Children and adolescents should use melatonin only under pediatric supervision, particularly given concerns about developmental effects. People with seizure disorders, depression, or bleeding disorders should also exercise caution.

Interactions

Melatonin may interact with several medication classes. It can enhance the sedative effect of benzodiazepines, opioids, alcohol, and other CNS depressants. It may potentiate the action of anticoagulants and antiplatelet drugs, increasing bleeding risk. Melatonin can affect blood pressure medications and immunosuppressants. Caffeine, fluvoxamine, and certain SSRIs can raise melatonin blood levels by inhibiting its metabolism. Birth control pills may also increase circulating melatonin.

Frequently asked questions

How much melatonin should I take?⌄

Start with the lowest effective dose, often 0.3 to 1 mg, taken 30 to 60 minutes before bed. Higher doses are not necessarily better and may increase morning grogginess.

Is melatonin habit-forming?⌄

Melatonin is not considered physically addictive and does not appear to cause tolerance or withdrawal in most studies. However, psychological reliance can develop, and using it nightly long-term has not been thoroughly studied.

Can I take melatonin every night?⌄

Long-term nightly use has limited safety data. For short-term issues like jet lag or temporary insomnia, melatonin is generally considered safe. For chronic sleep problems, consult a clinician to address underlying causes.

Will melatonin make me sleep through the night?⌄

Melatonin primarily helps with falling asleep rather than staying asleep. Extended-release formulations may help with sleep maintenance, especially in older adults whose endogenous melatonin is reduced.

Can children take melatonin?⌄

Pediatric use should be supervised by a clinician. Behavioral sleep approaches are typically the first line. Melatonin can be appropriate for children with ADHD or autism who have sleep difficulties, but doses should be conservative.

References

NIH Office of Dietary Supplements — ODS link
Wikidata: Melatonin — Wikidata link
PubChem: Melatonin (CID 896) — PubChem link

Track Melatonin with Pilora

Set up dose reminders, check interactions, and join the community in the Pilora iPhone app.

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Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you're pregnant, breastfeeding, on medications, or managing a chronic condition.