Melatonin and sleep: what to know before taking it

A natural hormone and a product are not the same

Your body produces melatonin in response to darkness as part of its daily timing system. Light at night can affect production. Taking a product adds melatonin from outside the body, so the hormone’s natural presence does not make every product or dose suitable for everyone.

Before choosing a product, define what you want to address: trouble falling asleep at a particular time, nighttime awakenings or adjustment after a flight. Different concerns can require different assessment and treatment.

When might its use be considered?

Evidence differs by condition. Melatonin has been studied for problems including sleep-timing disorders and jet lag. That does not establish it as an effective treatment for every case of insomnia. Persistent insomnia warrants assessment and consideration of treatments such as CBT-I.

When reading a study or marketing claim, check who was studied: adults or children, people with a specific condition or healthy participants, and what the treatment aimed to achieve. Improvement in one group does not guarantee your result.

For more information on the subject: Insomnia: why can't I sleep, and what can help?.

Why does timing matter?

Melatonin affects the body clock, so timing matters alongside the formulation and dose. Immediate-release and prolonged-release products are not necessarily suited to the same purpose. This guide does not recommend an individual dose or schedule.

Bring the exact product name and label to your consultation and describe your actual sleep and wake-up times. Ask what to do if you miss a dose or your routine changes. Do not independently add another dose in the middle of the night.

Children: seek advice before adding it to bedtime

Before giving a child melatonin, consult a pediatric clinician and discuss the sleep difficulty. Evidence on long-term safety in children is limited. Availability without a prescription in another country does not determine whether it is appropriate for your child.

Describe wake-up times, naps, screens, the bedtime routine and daytime effects. Store products out of children’s reach, especially those that resemble sweets. Do not share a product prescribed for one child with a sibling without professional guidance.

Side effects and other medicines

Melatonin can cause effects such as daytime sleepiness, headache, dizziness or nausea. Check compatibility with other medicines and supplements and with circumstances such as pregnancy or breastfeeding. “Natural” is not an adequate assurance of safety.

Make one list of everything you take, including supplements. Do not drive if you feel drowsy. Discuss new symptoms with a doctor or pharmacist rather than increasing the dose in response to one poor night.

How can you tell whether it is helping?

Agree on a clear goal with the clinician, such as a change in time to fall asleep or improvement in daytime functioning. Arrange a review point and a plan if there is no benefit. Remaining tablets in a packet are not a reason to continue automatically.

During the agreed period, you can record dose timing, estimated sleep times and any symptoms. Distinguish an observed change from a possible explanation: workload, wake-up times or screen habits may have changed at the same time.

What to record before an appointment