Why melatonin dosing matters more than the brand
Melatonin is the most widely used over-the-counter sleep aid in the United States, and it is also the most widely misused. A 2023 JAMA analysis of 25 commercial melatonin gummies found that 88% were inaccurately labeled, with actual doses ranging from 74% below to 347% above the stated amount. The bigger issue, though, is that the standard 5–10 mg dose sold in most pharmacies is 10–30 times higher than the dose your own pineal gland produces at night. More melatonin does not mean better sleep — it usually means more grogginess, blunted morning alertness, and a higher chance of vivid dreams or next-day headache.
What melatonin actually does (and what it does not do)
Melatonin is a chronobiotic, not a sedative. Its job is to tell your brain what time it is, not to knock you out. It binds to MT1 and MT2 receptors in the suprachiasmatic nucleus and signals the start of biological night. This is why it works beautifully for circadian rhythm problems — jet lag, shift work, delayed sleep phase — and only modestly for ordinary insomnia. A 2017 meta-analysis in PLoS One found that melatonin reduces sleep onset latency by an average of 7 minutes and increases total sleep time by 8 minutes in adults with primary insomnia. Useful, but not transformative.
The evidence-based dose for adults: 0.3–0.5 mg
Dr. Richard Wurtman and his MIT lab spent two decades demonstrating that 0.3 mg of melatonin reproduces normal nighttime blood levels and works as well as or better than 3 mg or 5 mg for sleep onset, without next-day grogginess. The American Academy of Sleep Medicine recommends 0.5–5 mg for circadian disorders, and most sleep physicians now start patients at 0.5 mg. For most adults, anything above 1 mg is a pharmacological dose, not a physiological one.
When to take it: timing beats dose
For falling asleep at a normal bedtime, take 0.5 mg about 30 minutes before bed. For phase advance (going to bed earlier than your body wants — for example, you fall asleep at 2 a.m. and want 11 p.m.), take a low dose 4–6 hours before your target bedtime. For phase delay (going to bed later — rare, usually for night-shift adjustment), take it in the morning after your shift. Taking melatonin at the wrong time can actually worsen circadian misalignment.
Jet lag protocol
Eastward travel (e.g. US to Europe): 0.5 mg melatonin at local bedtime for 3–5 nights starting the night you arrive. Westward travel (e.g. Europe to US): melatonin is less helpful — bright morning light at the destination matters more. For crossings of 5+ time zones, start the day before travel: take 0.5 mg at the destination's bedtime, shift your wake time by 1 hour per day toward the new schedule, and get aggressive morning sunlight on arrival.
Shift work protocol
For permanent night shift workers, take 0.5–3 mg about 30 minutes before your daytime sleep period. Use blackout curtains and a sleep mask to suppress daytime light, which is the dominant circadian signal. For rotating shifts, melatonin is more limited — the circadian system cannot fully adapt to schedules that change every few days.
Insomnia in older adults: a special case
Endogenous melatonin production drops 70–80% between ages 20 and 70. For adults over 55, prolonged-release melatonin (2 mg, available by prescription in many countries) has stronger evidence than immediate-release for chronic insomnia, with a 2023 Cochrane review confirming small but reproducible improvements in sleep quality.
Side effects and interactions
Even at low doses, melatonin can cause headache, daytime drowsiness, dizziness, and vivid dreams. It interacts with blood thinners (warfarin), immunosuppressants, diabetes medications, and birth control. It can lower blood pressure and blood glucose modestly. It should not be combined with alcohol or other sedatives. Pregnant or breastfeeding women should avoid it.
Who should not take melatonin
Children and adolescents (except under specific medical supervision for autism, ADHD-related sleep issues, or delayed sleep phase), people with autoimmune conditions, anyone on blood thinners, pregnant or breastfeeding women, and people with a history of depression or seizure disorders should consult a doctor first.
What about extended-release, sublingual, and gummies?
Extended-release (XR) is preferable for people who fall asleep fine but wake at 3 a.m. Sublingual or liquid forms act fastest and are the right choice for jet lag at bedtime. Gummies are convenient but often the most mislabeled and contain sugar — a poor choice for nightly use. Always pick a USP-verified or NSF-certified product.
How to taper off melatonin
Melatonin is not addictive in the way benzodiazepines are, but psychological dependence is real. Taper over 1–2 weeks: halve the dose for 5 nights, halve again for 5 nights, then skip every other night, then stop. Reinforce sleep hygiene during the taper — fixed wake time, morning sunlight, dim evenings.
Comparing melatonin to alternatives
Magnesium glycinate (200–400 mg) has solid evidence for sleep maintenance in deficient adults. L-theanine (200 mg) reduces anxiety-driven sleep onset issues. Glycine (3 g) lowers core body temperature and shortens sleep latency. CBT-I outperforms all supplements for chronic insomnia. Melatonin's unique value is circadian — for jet lag, shift work, or delayed sleep phase, nothing else compares.
FAQ
Is it safe to take melatonin every night? Short-term (under 3 months) at low doses is well-tolerated. Long-term safety beyond 6 months is less studied. Can I overdose? Acute toxicity is rare, but doses above 10 mg increase side effects without improving sleep. Does melatonin help anxiety? Modestly — it has mild anxiolytic effects but is not a primary anxiety treatment. Why do I feel groggy the next day? Almost always because the dose is too high. Drop to 0.3–0.5 mg.
Bottom line
Use 0.3–0.5 mg, 30 minutes before bed, for short stretches when you have a clear circadian reason to use it. Skip it for ordinary stress-driven insomnia — fix sleep hygiene and consider CBT-I instead. If you have been taking 5–10 mg nightly for months and still struggle to sleep, the dose is the problem, not the solution.