Melatonin Dose for Adults: What Actually Works

What does melatonin actually do?

Melatonin is a hormone produced by the pineal gland in response to darkness. It signals to the body that it is time to prepare for sleep — it does not cause unconsciousness the way a sedative does. The peak rise of melatonin typically occurs about two hours before your habitual sleep time.

As a supplement, melatonin works primarily by signaling a shift in your internal clock. This makes it well-suited for conditions where timing is off: - Jet lag: Research supports melatonin for both preventing and treating jet lag when crossing multiple time zones 1Ref 1Herxheimer A, Petrie KJ (2002).Melatonin for the Prevention and Treatment of Jet Lag.Low doses (0.5–3 mg) of melatonin are effective for jet lag and circadian shifting; higher doses do not improve efficacy - Shift work: Helps night shift workers sleep at unusual hours - Delayed sleep phase: People whose natural sleep timing is very late (falling asleep at 2 or 3 am) can shift earlier with timed melatonin

For ordinary insomnia — where timing is not the core problem — melatonin produces modest effects on sleep onset and much smaller effects on total sleep time or middle-of-the-night waking.

What is the right melatonin dose for adults?

This is where evidence and commercial practice diverge significantly. Most supplements sold in the United States contain 5, 10, or even 20 mg of melatonin. Research on melatonin for jet lag — among the most studied uses — has found that doses of 0.5 to 3 mg are as effective as higher doses and produce fewer side effects 1Ref 1Herxheimer A, Petrie KJ (2002).Melatonin for the Prevention and Treatment of Jet Lag.Low doses (0.5–3 mg) of melatonin are effective for jet lag and circadian shifting; higher doses do not improve efficacy.

Physiological melatonin levels at peak are much lower than what most supplements deliver. Higher doses do not produce stronger sleep effects; they largely produce supraphysiological blood levels that clear slowly, potentially causing grogginess the next morning.

A practical starting point: - 0.5 to 1 mg: A reasonable physiological starting dose, particularly if you are sensitive to supplements or sleep aids - 2 to 3 mg: What most sleep medicine guidance references for adults; adequate for most people - 5 mg or higher: Common on store shelves but not supported by evidence for better sleep; associated with more next-day grogginess

Because melatonin is sold as a dietary supplement rather than a prescription drug in the United States, labeling accuracy and actual contents have varied in studies — another reason to start at the lower end.

When should I take melatonin for sleep?

Timing matters as much as dose. Melatonin works by shifting the body clock, so the effect depends on when you take it relative to your current and desired sleep time.

For falling asleep at your normal time: Take it 30 to 60 minutes before your intended bedtime.

For jet lag going east (losing hours): Take melatonin at the local bedtime at your destination for two to four nights after arrival. Eastward travel is harder to adjust to, and melatonin helps advance your clock 1Ref 1Herxheimer A, Petrie KJ (2002).Melatonin for the Prevention and Treatment of Jet Lag.Low doses (0.5–3 mg) of melatonin are effective for jet lag and circadian shifting; higher doses do not improve efficacy.

For jet lag going west (gaining hours): The adjustment is easier and melatonin has more modest benefit. Some people take it at the new local bedtime.

For delayed sleep phase: Take a low dose (0.5 to 1 mg) several hours before your actual current sleep time — gradually moving it earlier to shift your clock forward. This requires a consistent schedule to work.

What melatonin does not do well

Melatonin is frequently used as a general sleep aid for chronic insomnia — waking frequently, difficulty staying asleep, unrefreshing sleep. For these problems, evidence for melatonin is weak to modest.

The most effective treatment for chronic insomnia is cognitive behavioral therapy for insomnia (CBT-I), which has durable benefits that continue after treatment ends 2Ref 2Edinger JD, Arnedt JT, Bertisch SM, et al. (2021).Behavioral and Psychological Treatments for Chronic Insomnia Disorder in Adults: An American Academy of Sleep Medicine Clinical Practice Guideline.CBT-I has stronger evidence than melatonin for chronic insomnia and is the recommended first-line treatment3Ref 3Trauer JM, Qian MY, Doyle JS, Rajaratnam SMW, Cunnington D (2015).Cognitive Behavioral Therapy for Chronic Insomnia: A Systematic Review and Meta-analysis.Meta-analysis confirming durable CBT-I benefits for chronic insomnia. Melatonin does not address the conditioned arousal, thought patterns, and behavioral habits that sustain chronic insomnia.

For people who want something over the counter to help with difficulty falling asleep (as opposed to staying asleep), a low-dose melatonin taken at the right time is a reasonable option with a good safety profile. It is not a substitute for addressing underlying causes.

Is melatonin safe for regular use?

Melatonin has a favorable safety profile compared to prescription sleep medications. It does not create significant physical dependence and does not cause the morning-after cognitive impairment associated with many prescription sedatives.

Known considerations: - Next-day grogginess is dose-dependent and more common at high doses; a reason to use the lowest effective dose - Interaction with blood thinners: Melatonin may have modest anticoagulant effects; discuss with your clinician if you take warfarin or similar medications - Pregnancy: Safety data is limited; avoid unless a clinician specifically recommends it - Driving: Because melatonin causes some sedation, avoid driving or operating machinery for a few hours after taking it

Long-term daily use has not been shown to suppress the body's own melatonin production in controlled studies, though the evidence base for very prolonged use is thinner.