Does Melatonin Help You Sleep?

It’s 1 a.m. and the little bottle is on the nightstand. You’ve read that it’s natural, so how risky can it be? You swallow two, then lie there, wondering if you should have taken three.

Where it has evidence

The NCCIH¹ says the best evidence is for jet lag. Studies suggest melatonin may be better than a placebo at reducing jet lag symptoms after long flights, especially eastward.

It also reports modest benefit in delayed sleep-wake phase disorder, where the body clock runs late. People fell asleep about 34 minutes earlier when melatonin was combined with regular bedtime routines.

Where it doesn’t

For ongoing insomnia, the NCCIH¹ says medical guidelines cite not enough strong evidence on the effectiveness or safety of melatonin supplements to recommend them. If you lie awake because of stress, hot flashes, a snoring partner or pain, a hormone for body-clock timing may not touch the cause. See trouble falling asleep and waking at 3 a.m..

The label problem

The NCCIH¹ says most supplements are synthetic, and that quality varies. A 2017 study it cites found 26 percent of the products it tested contained serotonin, and most didn’t match their labeled amounts. A 2023 study of children’s gummies found 22 of 25 over-the-counter products were inaccurately labeled, with some containing up to 3.5 times the advertised dose.

That’s why “how much should I take” is hard to answer from the bottle alone. Ask your pharmacist or clinician.

Safety

The NCCIH¹ says short-term use appears safe for most people, but information on long-term safety is lacking. It says to check with your provider before use, especially if you take blood thinners or have epilepsy.

The NHS² lists common side effects: daytime sleepiness or tiredness, headache, stomach ache, nausea, dizziness, feeling irritable or restless, dry mouth, dry or itchy skin, pains in the arms or legs, and strange dreams or night sweats. If you already sweat at night, see why you sweat so much at night. Serious side effects are rare, the NHS says, at fewer than 1 in 1,000 people, and include symptoms of depression, vision changes, fainting, confusion, unexplained bruising or bleeding, and rarely anaphylaxis, which needs emergency care.

The basics that have more behind them

The Centers for Disease Control and Prevention (CDC)³ says adults 18 to 60 need 7 or more hours of sleep a night, and lists the habits that help:

• A fixed sleep and wake time every day
• A quiet, relaxing bedroom at a cool temperature
• No screens for at least 30 minutes before bed
• No heavy meals or alcohol before bed
• Less caffeine in the afternoon and evening
• Regular exercise

Our article on snoring and on sleep apnea in women covers causes of poor sleep that no supplement fixes.

The play

Try this: two weeks of the CDC basics

Pick a wake-up time and keep it every day, weekends included. Put screens away 30 minutes before bed. Cut caffeine after midday.

Each morning, write down when you fell asleep, how many times you woke and how you felt.

If you still want melatonin, talk to a pharmacist about timing and dose first, and keep notes on how you feel.

When to get checked

Don’t wait if

1. Emergency

   Get emergency care for throat or face swelling, severe trouble breathing, or loss of consciousness after taking any supplement or medicine.

Book an appointment if any of these fit:

• Sleep trouble lasts weeks despite the basics
• You’re tired all day despite 7 or more hours in bed
• You snore loudly or someone has seen you pause for breath
• You wake with a headache or a dry mouth most days
• Your sleep changed around menopause and nothing helps
• You take melatonin regularly and have side effects, or want to keep taking it long term

A pill can nudge a body clock. It can’t fix a bedroom, a bladder or a breathing problem, and a diary can show which one you have.