Melatonin has recently become a popular supplement for people who want to sleep better. It also plays a role in reproductive health. However, research is unclear about whether melatonin is actually safe to take while pregnant.

Melatonin is a hormone that your body produces naturally. Among other things, it’s responsible for keeping your body clock on a 24-hour cycle. This cycle is the circadian rhythm that ensures you sleep at night and wake up in the morning. Sometimes people try taking additional supplements of melatonin to improve their quality of sleep.

Both the ovaries and placenta make high levels of melatonin and use the hormone throughout pregnancy and delivery. Melatonin levels rise significantly at 24 weeks of pregnancy and rise even more again after 32 weeks.

Melatonin works with oxytocin to promote labor and delivery. Melatonin levels are higher are night, which might be why many women go into labor in the evening and early morning.

Melatonin is also found in amniotic fluid, and babies rely on their mother’s melatonin supply while they are in utero and until 9–12 weeks after they are born. So, melatonin supplements can affect both a woman and her baby.

Read on to learn more about the benefits and risks of melatonin in pregnancy.

Is it safe?

Your body makes its own melatonin all the time. Whether you should take additional supplements is debated. Just because something is natural doesn’t mean it’s completely safe. If you take melatonin supplements, tell your doctor so they can be aware of any potential complications.

Melatonin hasn’t been proven safe in pregnancy, and there is no standard dosage, which makes it tricky to buy off the shelf and take on your own.

Melatonin is considered safe for short-term use, but its long-term effects have not been studied.

One animal study found that additional melatonin during pregnancy negatively affected maternal weight, baby birth weight, and baby mortality.

Potential side effects include:

  • drowsiness
  • nausea
  • headache
  • dizziness

What are the benefits of melatonin?

Human studies of the effects of melatonin on pregnancy and babies are in the earliest stages. Some animal tests have shown positive correlations between melatonin and pregnancy outcomes, however.

The following are some possible benefits of melatonin for fetuses:

Possible benefits for pregnant women include:

Much more is needed in terms of human studies to show if supplemental melatonin should be used specifically for these conditions.

How to take melatonin supplements

Most melatonin supplements come as a dry pill that you take by mouth.

The typical dose of melatonin is 1–3 mg. This dosage elevates melatonin levels 20 times your normal level. Ask your doctor for their recommendation on how much to take.

If you do take melatonin supplements, it’s probably a good idea to take them at the same time every day since it affects your sleep-wake cycle.

Where can you purchase melatonin?

Always talk to your healthcare provider before beginning new supplements.

You do not need a prescription to buy melatonin. It’s easily found in most health food stores and drugstores. The U.S. Food and Drug Administration (FDA) does not regulate supplements as strictly as other medications, so quality is not guaranteed. The FDA ensures supplement bottles are not tampered with or mislabeled.

It’s up to each brand to make sure their supplements are safe and pure. Find a trustworthy brand of supplements by researching, asking your doctor, and asking a health food store owner.

Tips for sleep

Sleep is important for everyone. Sleep can be especially difficult for pregnant woman. Talk to your doctor if you’re having trouble sleeping well at night.

Before you reach for any kind of medication to induce better sleep, there is a range of lifestyle behaviors you can choose to support better sleep.

1. Screen time curfew

Turn off all glowing screens an hour before you hope to fall asleep. The light emitted affects your body’s natural hormones and circadian rhythms for sleep.

2. Bedroom hygiene

Keep your room free of clutter, and set the temperature to around 65°F. You may also want to consider room-darkening curtains to reduce the light in your room.

3. Up your pillow game

People rave about their pregnancy pillows, but you may be able to get the same effect by placing pillows on your backside, between your knees, and under your belly.

4. Wake up and go to sleep at the same time every day

The best way to fall asleep at a regular hour each night is to wake up at a regular time each morning. This practice works with your body’s hormones to keep your circadian rhythm in tune.

5. Calming practices

Focus on doing calming activities an hour before bed, like taking a warm bath or shower, reading a book, meditating, or writing in a journal.

6. Safe sleep aids

Unisom is a sleep aid that may be safe to use during pregnancy. Ask your doctor if using this or another sleep aid is right for you.


Melatonin is a popular natural sleep aid. It’s mostly considered safe for short-term use, but it has not been proven safe for pregnancy. Talk to your doctor before taking melatonin during pregnancy.