Can You Take Melatonin While Pregnant: Unanswered Questions

written by / September 15, 2022
Can You Take Melatonin While Pregnant

Pregnant women often face difficulties sleeping. Excitement about becoming a new mom, hormonal changes, and many other factors can contribute to losing sleep. So, it’s no surprise that many of them are interested in taking sleep aids, such as melatonin.

But is melatonin safe for expecting mothers? Or babies? 

Let’s find out!

Can You Take Melatonin While Pregnant?

There still isn’t enough scientific evidence proving that melatonin is safe to take during pregnancy. 

There’s still a lot that we don’t know — what would be the appropriate dosage of melatonin supplements for pregnant women, how this hormone would affect the pregnant woman (and the baby) in the long run, what are the most common side effects, etc. 

There aren’t many human studies tackling this topic out there, and the results of certain animal studies didn’t look too promising. For example, an animal study suggested that taking melatonin while pregnant may affect babies’ growth as well as mortality.

This is why medical professionals don’t routinely prescribe melatonin supplements as sleep regulators to expecting mothers. 

Melatonin and Pregnancy

Our bodies naturally produce melatonin, and they keep doing so during pregnancy. 

Melatonin production increases drastically in the first trimester. The levels of this hormone increase after the 24th week of gestation and once again in the 32nd week of pregnancy.

This is because, besides the melatonin our bodies would normally produce, additional reserves of this hormone are produced by the placenta.

The mother’s melatonin levels greatly affect the baby. Namely, melatonin can travel from the mother to the baby, crossing the placenta, and bind to the unborn baby’s receptors. 

And this is why taking melatonin during pregnancy may pose a great risk

Which Expecting Mothers May Still Get Melatonin Prescribed?

Some medical professionals may decide to prescribe melatonin to their pregnant patients (or those who are trying to conceive). There’s a valid reason for this, which isn’t related to the circadian rhythm and sleep at all. 

Namely, melatonin plays a crucial role in fertility. This hormone supports ovarian function, ovulation, embryo implantation, and uterus growth. What’s more, disrupted melatonin production may lead to infertility and miscarriages.

This is why some professionals advise melatonin supplementation for women who are struggling to get pregnant due to some underlying medical issues (e.g., endometriosis).

Additionally, some medical professionals may prescribe melatonin supplements to pregnant women with preeclampsia

How Much Melatonin Is Safe During Pregnancy?

A safe melatonin dose may greatly vary depending on many factors (a good starting dosage may vary from 0.2 mg to 5 mg). 

Medical professionals recommend starting with lower doses to prevent an overdose (as pregnant women typically have naturally higher melatonin levels). 

Still, knowing that melatonin is still greatly unresearched as a sleep aid for pregnant women, it’s best to refrain from it (unless it was prescribed to you by a doctor) and opt for other sleep aids, which are more fit for pregnant women. 

Which Sleep Aids Can I Use During Pregnancy?

While medication may not be an option, there are some other things moms-to-be can do to resolve their sleep troubles:

  • Keep strict sleep hygiene
  • Practice relaxation (e.g., yoga, deep breathing, stretching, etc.)
  • Limit caffeinated drinks and the amount of liquid you drink before bed
  • Have light dinner
  • Drink warm milk before bedtime
  • Take quick naps during the day
  • Use pregnancy pillows, a comfortable mattress, etc., for support
  • Keep the bedroom cool and dark
  • Get a massage

And be patient. If you can’t fall asleep in 30 minutes after crawling into bed — get up, read, listen to music, and get back to bed when you start feeling sleepy again.


Though melatonin is a well-accepted natural sleep aid, it may not be safe to take during pregnancy, just like many other natural things (e.g., certain types of seafood). 

As you have had the chance to see, there simply isn’t enough scientific evidence that taking melatonin while pregnant is safe for expecting mothers, so it definitely wouldn’t be wise to take it on your own. 

Opt for alternative measures to improve your sleep, and make sure to discuss the intake of any supplements (natural or synthetic) with your medical provider. 


Who may take melatonin during pregnancy?

Though melatonin isn’t routinely prescribed to pregnant women, there are cases when medical professionals decide to prescribe this type of supplement to expecting mothers.

For example, pregnant women with preeclampsia may get melatonin supplements to regulate their melatonin levels, which are typically very low. 

How much melatonin should I take during pregnancy?

There aren’t enough clinical trials that prove that melatonin supplementation is safe for either the mom-to-be or the baby. Therefore melatonin typically isn’t prescribed to pregnant women unless their doctor sees that fit. 

Still, if you suffer from preeclampsia, your doctor may prescribe 0.2–5 mg of melatonin (or more if need be). Otherwise, various relaxation techniques (and even cognitive behavioral therapy) are prescribed to alleviate insomnia instead.

Will melatonin harm my baby?

The long-term effects of melatonin on the expecting mother and the baby are still greatly unknown. This is precisely the reason why this supplement isn’t prescribed to moms-to-be. 

Some studies show that melatonin may benefit the baby (maintain its circadian rhythm and sleep patterns, prevent brain defects and preterm delivery). But this is related to natural melatonin, produced by the mother’s brain and placenta — not supplements. 

On the other hand, a handful of animal studies indicate that melatonin supplements may negatively affect the baby’s birth weight and mortality.

At medical school, it was easy to realize that sleep is crucial while studying during the many sleepless nights I spent. As a new mom, when the lack of sleep became even more evident, this was the real moment when I started appreciating the benefits of a good night’s sleep. Since sleeping is so essential to our health and immune system, I took it upon myself to educate people on different aspects of sleep by sharing the valuable information I have learned.