Melatonin
Melatonin is a hormone naturally produced by the pineal gland that regulates the sleep-wake cycle. Supplemental melatonin is most effective for circadian rhythm issues like jet lag and shift work, though its benefits for general insomnia are more modest than commonly believed.
Quick Verdict
Effective for sleep timing (jet lag, shift work). Less impressive for general insomnia. Lower doses often work better. Quality varies wildly between brands.
Best used strategically for jet lag, shift work, or circadian rhythm disorders rather than as a nightly sleep aid. Start with the lowest dose (0.5mg) — higher doses are not more effective and cause more grogginess. Choose third-party tested brands given the quality issues in this category.
At a Glance
Dose
0.5-3mg per night
When to Take
30-60 minutes before desired sleep time. For jet lag: take at destination bedtime starting 1-2 days before travel.
Best Form
Immediate-release for sleep onset; extended-release for sleep maintenance. Sublingual for faster onset.
Evidence
69% avg
What It Is
Melatonin is an endogenous hormone produced by the pineal gland in response to darkness, serving as the body's primary signal for nighttime and sleep timing. Its secretion follows a circadian rhythm, rising in the evening, peaking between 2-4 AM, and dropping before dawn. Supplemental melatonin is available over the counter in most countries (though prescription-only in some EU nations) in doses ranging from 0.5mg to 10mg. Importantly, melatonin is primarily a circadian rhythm regulator rather than a traditional sleeping pill — it signals to the body that it is time to sleep rather than directly inducing sedation. Studies have shown massive variability in the actual melatonin content of commercial supplements, with some products containing up to 478% of their labeled dose.
How It Works
Melatonin binds to MT1 and MT2 receptors in the suprachiasmatic nucleus (SCN) of the hypothalamus, the brain's master circadian clock. MT1 receptor activation promotes sleepiness by inhibiting wake-promoting signals from the SCN. MT2 receptor activation shifts circadian phase timing, which is why melatonin is particularly effective for jet lag and circadian rhythm disorders. Unlike GABAergic sleep aids (benzodiazepines, Z-drugs), melatonin does not force sleep but rather opens the 'sleep gate' by reinforcing the circadian signal. It also has mild hypothermic effects, lowering core body temperature which facilitates sleep onset. Additionally, melatonin acts as an antioxidant, though the clinical relevance of this at supplemental doses is unclear.
Evidence by Goal
jet lag
Strong evidence for reducing jet lag symptoms when crossing 5+ time zones, particularly for eastward travel. Take at destination bedtime.
circadian rhythm
Effective for delayed sleep phase syndrome, shift work adaptation, and non-24-hour sleep-wake disorder. Timing of dose is critical.
sleep
Reduces sleep onset latency by 7-12 minutes on average. More of a timing signal than a sedative. Benefits are modest for general insomnia.
Dosage & Usage
Standard Dose
0.5-3mg per night
Loading Protocol
Not applicable. Lower doses (0.5-1mg) are often as effective as higher doses. More is not better.
Timing
30-60 minutes before desired sleep time. For jet lag: take at destination bedtime starting 1-2 days before travel.
Best Form
Immediate-release for sleep onset; extended-release for sleep maintenance. Sublingual for faster onset.
📅 What to Expect
30-60 min
Onset of drowsiness signal. Easier to fall asleep.
Day 1-3
Sleep onset improves by 7-12 minutes on average.
Week 1-2
Circadian rhythm shifts if timing is consistent. Jet lag resolves.
Ongoing
No tolerance develops. Same dose remains effective indefinitely.
🎯 How to Know It's Working
Fall asleep 10-15 min faster
More consistent sleep schedule
Less jet lag on travel
If not working: If still can't fall asleep, your issue may not be circadian. Try lower dose (0.5mg) or address sleep hygiene first.
🏷️ Buying Guide
✓ Look For
- • Low dose: 0.5-3mg (higher is NOT better)
- • Third-party verified (huge quality variation in this category)
- • Immediate-release for sleep onset or extended for maintenance
✗ Avoid
- • Doses above 5mg (unnecessary, more side effects)
- • Gummies with added sugar
- • Products without third-party testing (content varies -83% to +478%)
🥗 Get It From Food
🛡️ Safety Profile
Common Side Effects
- • morning grogginess (often from excessive dose)
- • vivid or unusual dreams
- • mild headache
- • dizziness
⚠️ Contraindications
- 🚫 autoimmune conditions (theoretical concern — melatonin modulates immune function)
- 🚫 seizure disorders (may lower seizure threshold in some)
💊 Drug Interactions
- • blood thinners (may enhance anticoagulant effect)
- • immunosuppressants (may counteract)
- • diabetes medications (may affect glucose metabolism)
- • birth control pills (may increase natural melatonin levels)
Long-Term Safety
Generally considered safe for medium-term use (months). Long-term safety data is limited but no serious signals have emerged. Unlike traditional sleep medications, melatonin does not appear to cause dependency or rebound insomnia. Main concern is unregulated supplement quality — third-party tested products recommended.
👥 Who Benefits Most
Best For
- ✓ frequent travelers crossing time zones
- ✓ shift workers
- ✓ those with delayed sleep phase (night owls)
- ✓ older adults with diminished natural melatonin production
- ✓ blind individuals with non-24-hour circadian rhythm
Less Effective For
- — those with general insomnia not related to circadian rhythm
- — people already producing adequate melatonin
- — those whose insomnia is driven by anxiety or pain
📚 Key Research
3 peer-reviewed studies supporting this supplement's effects.
Meta-analysis: melatonin for the treatment of primary sleep disorders
Ferracioli-Oda E, Qawasmi A, Bloch MH · PLoS ONE (2013)
Meta-analysis of 19 RCTs found melatonin significantly reduced sleep onset latency (7.06 min), increased total sleep time (8.25 min), and improved overall sleep quality, with effects sustained over time.
Melatonin for the prevention and treatment of jet lag
Herxheimer A, Petrie KJ · Cochrane Database of Systematic Reviews (2002)
Cochrane review found melatonin is remarkably effective for preventing or reducing jet lag when crossing 5+ time zones, particularly for eastward travel. Daily doses of 0.5-5mg were similarly effective.
Melatonin Natural Health Products and Supplements: Presence of Serotonin and Significant Variability of Melatonin Content
Erland LA, Bhakta P · Journal of Clinical Sleep Medicine (2017)
Analysis of 31 melatonin supplements found actual content ranged from -83% to +478% of labeled dose. 26% of products also contained serotonin. Highlights importance of quality testing.
💰 Cost & Forms
Estimated Monthly Cost
$5-15
🔗 Related Evidence Reviews
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