When Is It Safe to Take Melatonin Every Night? Sleep Experts Explain the Risks

How melatonin works

The brain naturally produces melatonin in response to darkness. The hormone helps regulate circadian rhythms, the internal clock that influences when people feel ready to sleep and wake.

Supplements mimic the role of natural melatonin. Jamie K. Alan, a pharmacology and toxicology professor at Michigan State University, says the melatonin people consume is the same as the hormone their bodies make and promotes sleep in the same way.

Evidence for sleep problems

Melatonin may help reset sleep rhythms, but Christopher Winter, a sleep medicine specialist, says research has not found it effective for chronic insomnia. The American Academy of Sleep Medicine says evidence is not strong enough to recommend melatonin supplements for that condition.

Winter says he sees a role for occasional use related to jet lag or shift work, but not as a lasting fix for sleep problems. He recommends speaking with a doctor before using the supplement for trouble sleeping.

Dosage and safety concerns

Noah Siegel, medical director of Otolaryngology at Mass Eye and Ear, says one to two milligrams taken about half an hour before bedtime should be sufficient. The article discusses a study linking melatonin use with heart concerns, but notes that its users were identified through official health records. People taking over-the-counter supplements would not have been counted as melatonin users. Cardiologist Bradley Serwer says the study showed correlation, not causation; he theorizes that long-term use could affect natural production or heart receptors.

Use and popularity

Globally, people spent around $3.2 billion on melatonin in 2026, and that amount is expected to triple in the next decade. A National Center for Health Statistics survey found that 5.7% of Americans used an over-the-counter sleep medicine or supplement, including melatonin.

Winter says people seeking a lasting solution should look beyond relying on a capsule. The experts’ comments emphasize that regular use should be discussed with a doctor, especially when sleep difficulties persist.