Other Ingredients

Melatonin

Also known as: N-acetyl-5-methoxytryptamine, Sleep hormone

The sleep-wake hormone, taken as the most popular OTC sleep aid in the US — best for jet lag and falling asleep faster.

By IngredientWiki Editorial Team
Fact-checked by IngredientWiki Editorial Team
Updated 2026-09-26
2 min read

In short

Melatonin is a hormone your pineal gland releases in darkness to signal that it is time to sleep. As a supplement, it is the most widely used sleep aid in the United States. The evidence is strongest for jet lag and delayed sleep phase, and it modestly shortens the time it takes to fall asleep. Contrary to popular dosing, research suggests 0.5–3 mg is often as effective as larger doses — and causes fewer side effects.

Hormone released in darkness that regulates the circadian rhythm
Strongest evidence: jet lag and shifted sleep schedules
Typical useful dose: 0.5–3 mg, taken 30–60 minutes before bed
More is not better — high doses raise side effects without better sleep

What is Melatonin?

Melatonin is often called the sleep hormone, but its real job is subtler: it is the chemical signal of darkness. When evening light fades, the pineal gland releases melatonin, telling your body's internal clock that night has begun. Supplementing it does not sedate you like a sleeping pill — it nudges your circadian rhythm, which is exactly why it shines for jet lag and schedule shifts, and why its effect on ordinary insomnia is modest.

Where it comes from

Natural sources

Produced endogenously by the pineal gland in darkness
Tart cherries and a few foods contain trace amounts (too little to matter clinically)
Supplemental melatonin is produced synthetically, not extracted from animals

How it's made

Commercial melatonin is synthesized in laboratories; doses on labels are often inaccurate, so third-party testing matters.

What it does in products

Benefits

Jet lag

strong evidence

Meta-analyses consistently find melatonin reduces jet lag symptoms when taken near bedtime at the destination, especially crossing five or more time zones.

Delayed sleep phase (night owls)

strong evidence

Small doses taken hours before habitual bedtime can shift sleep earlier in people with delayed sleep-wake phase disorder — one of its clearest clinical uses.

Falling asleep faster

moderate evidence

In people with insomnia, melatonin shortens the time to fall asleep by roughly 7–12 minutes on average and slightly improves total sleep time — real but modest.

Children's sleep

moderate evidence

Melatonin helps some children with ADHD or autism-spectrum conditions fall asleep, and short-term use under pediatric guidance is common — though long-term safety in children is not fully established.

Side effects & safety

Morning grogginess (uncommon)More common at doses above 5 mg; lowering the dose usually fixes it.

Vivid dreams or headache (uncommon)Usually transient.

Accidental ingestion by children (rare)Gummy formulations look like candy and are a leading cause of pediatric poison-center calls — store locked away.

Safety considerations

Melatonin has limited safety data in pregnancy; consult your provider before use.
Adds to the effects of sedatives, alcohol, and other sleep medications.
May affect immune function — caution with immunosuppressant therapy.
May raise blood pressure slightly if taken with certain blood-pressure medications (timing matters).
Not for: Autoimmune conditions (use under supervision only)
Not for: Unsupervised use in young children

How it's used

In supplements

Start with 0.5–1 mg, taken 30–60 minutes before bed; increase to 3 mg if needed. For jet lag, take 0.5–3 mg near local bedtime at the destination for a few days. Many products sell 5–10 mg; those doses are rarely necessary for sleep onset.

Regulatory status

Dietary supplement under DSHEA. Unlike prescription sleep aids, it is not FDA-approved as a treatment for insomnia, and label quality varies — independent testing (USP/NSF) is recommended.

Why less melatonin is often more

A landmark MIT analysis found peak physiological effect at roughly 0.3 mg, and clinical reviews consistently find no additional sleep benefit above 3 mg — while next-day grogginess rises with dose. The 10 mg gummies on shelves reflect marketing, not pharmacology. If 3 mg does not help, the problem may be sleep hygiene or timing, not the dose.

Frequently asked questions

What is the best time to take melatonin?

For sleep onset, 30–60 minutes before bed. For shifting a late sleep schedule earlier, tiny doses (0.3–0.5 mg) several hours before your current bedtime are more effective than a big dose at bedtime — timing determines whether you shift earlier or later.

Is melatonin safe to take every night?

Short-term nightly use (weeks to a few months) appears safe for most adults. It is best used as a rhythm corrector rather than a permanent crutch; if insomnia persists beyond a few weeks, see a doctor rather than escalating the dose.

Is melatonin addictive?

No. Melatonin does not cause physical dependence or withdrawal like prescription sedatives, though some people become psychologically reliant. Tolerance is not a known issue — ineffectiveness usually reflects wrong timing or an underlying sleep problem.

The bottom line

Melatonin is a safe, non-addictive rhythm signal — excellent for jet lag and schedule shifts, modest for sleep onset. Start at 0.5–3 mg, time it correctly, and treat the gummies like medicine, not candy.

References

Melatonin: What You Need To Know. NCCIH (National Institutes of Health). https://www.nccih.nih.gov/health/melatonin-what-you-need-to-know
Melatonin compound summary. PubChem (National Library of Medicine). https://pubchem.ncbi.nlm.nih.gov/compound/896
Melatonin for jet lag (Cochrane review). Cochrane Database of Systematic Reviews. https://pubmed.ncbi.nlm.nih.gov/12076414/
Melatonin and sleep — literature search. PubMed (National Library of Medicine). https://pubmed.ncbi.nlm.nih.gov/?term=melatonin+sleep+onset+randomized