Melatonin for Sleep: The Evidence and the Correct Dose
Melatonin is one of the most misunderstood sleep supplements — and most people taking it are using the wrong dose. The research is clear: 0.5-1mg is the physiologically appropriate dose for most people. The 5-10mg doses commonly sold in pharmacies are 5-20 times higher than what the brain normally produces and can cause next-day grogginess and suppress natural melatonin production over time.
What Melatonin Actually Does
Melatonin is a circadian timing signal, not a sedative. It tells your brain that darkness has arrived and it's time to prepare for sleep — it doesn't directly produce sleep the way benzodiazepines or antihistamines do. This is why melatonin works well for circadian timing problems (jet lag, shift work, delayed sleep phase syndrome) but is less effective for straightforward insomnia where the timing of sleep is normal but sleep won't come.
When Melatonin Works Best
- Jet lag: The strongest evidence for melatonin. Take 0.5-3mg at the target bedtime of your destination for 2-4 nights. Eastward travel benefits most (advancing the clock is harder for the body).
- Shift work: 1-3mg before a daytime sleep period helps shift workers fall asleep despite light exposure.
- Delayed sleep phase syndrome: 0.5mg taken 5-6 hours before current natural sleep time gradually advances the sleep phase over weeks.
- General sleep onset difficulties: Modest evidence — helps reduce time to fall asleep by 7-12 minutes on average in meta-analyses. Weaker than magnesium glycinate for most people.
The Dose Problem
Physiological melatonin production peaks at 0.1-0.3mg during sleep. The 3-10mg doses sold in US pharmacies are pharmacological doses (5-100x physiological) producing supraphysiological blood levels. Problems with high doses: next-day grogginess, headache, vivid dreams, and potential suppression of natural melatonin synthesis with long-term high-dose use.
Correct approach: Start with 0.5mg (or 1mg maximum) taken 1.5-2 hours before target sleep time. If 1mg doesn't help, the issue is probably not melatonin deficiency — look at sleep hygiene, blue light exposure, cortisol, and consider magnesium glycinate + passionflower instead.
Melatonin vs Better Alternatives
For sleep onset difficulties: Magnesium glycinate (300-400mg, bedtime) > Passionflower (500mg) > Melatonin. Both have stronger evidence for sleep onset in non-circadian insomnia.
For jet lag: Melatonin 0.5-3mg is the clear first choice — nothing else works as well for advancing or delaying the circadian clock.
For anxious insomnia: L-theanine 200mg + Passionflower 500mg addresses the anxiety driving the insomnia — melatonin alone won't help.
Frequently Asked Questions
Does melatonin actually help you sleep?
For jet lag and circadian timing problems: yes, strong evidence. For general insomnia: modest evidence — reduces sleep onset time by 7-12 minutes on average in meta-analyses. For most people with insomnia, magnesium glycinate and passionflower produce more significant sleep improvement. Melatonin's strength is circadian timing, not general sedation.
What is the correct dose of melatonin?
0.5-1mg taken 1.5-2 hours before target sleep time. This is the physiologically appropriate dose — the brain normally produces 0.1-0.3mg during sleep. Higher doses (3-10mg) are not more effective and cause more side effects (grogginess, headache, vivid dreams). If 1mg doesn't help, the problem is likely not melatonin deficiency.
Can you take melatonin every night?
Short-term (2-4 weeks): safe at 0.5-3mg for jet lag and sleep onset. Long-term continuous use: evidence is limited, and high-dose chronic use may suppress natural melatonin synthesis. For ongoing sleep support, magnesium glycinate, passionflower and ashwagandha are better suited for long-term nightly use. Use melatonin for jet lag and short-term circadian adjustment; use other natural sleep aids for ongoing insomnia management.