Melatonin: A Guide to Proper Use

Millions of people take melatonin. It is sold as a sleep aid — though technically it is not a sleeping pill. It is a hormone, and its role in sleep is considerably more subtle than simply "turning sleep on."

What melatonin is and how it works

Melatonin is a hormone produced by the pineal gland in response to darkness. Its production begins approximately two hours before a person's habitual sleep time, peaks around 2 to 3 a.m., and declines toward morning. It does not "cause" sleep — it signals to the body that biological nighttime has begun.

Melatonin is essentially a timing marker. It synchronizes circadian rhythms. This is why it is useful for circadian rhythm disruptions — jet lag, shift work, delayed sleep phase disorder — but not necessarily for classical insomnia.

When melatonin works

Jet lag is the best-supported application. Taking melatonin in alignment with the destination's local time helps shift the circadian clock more quickly. The recommended approach: take it in the evening for a few days after crossing five or more time zones.

Delayed sleep phase disorder: small doses of melatonin taken several hours before the desired sleep time help shift the circadian phase earlier.

Shift work: can help adapt the rhythm when schedules change regularly.

Older adults: melatonin production decreases with age, and supplementation can help improve sleep quality in this group.

Dosage: less is more

This is the most frequently ignored point. Melatonin is sold in doses of 3, 5, and 10 mg in many countries. Research shows that the physiologically effective dose is 0.5 to 1 mg. Higher doses do not produce proportionally better results, but they can cause morning grogginess, nightmares, and hormonal disruption with long-term use.

For most purposes, 0.5 mg is sufficient and effective. If only 3 mg tablets are available, splitting them works well.

Timing matters

Melatonin taken as a circadian-shifting agent (for DSPD or jet lag) should be taken 5 to 6 hours before the desired sleep time. Taking it immediately before bed as a "sleeping pill" produces peak blood levels at sleep onset but minimal chronobiological effect.

What melatonin does not do

Melatonin does not treat chronic insomnia. It does not restore normal sleep architecture in insomnia. It is not a treatment for anxiety or depression, though it may modestly improve sleep in these conditions. For chronic insomnia, CBT-I is the correct choice; melatonin is a possible adjunct, not the primary treatment.

If you have been taking melatonin for months without benefit, this is likely not the right intervention for your situation. The underlying cause of the sleep disturbance is worth investigating.