There are not enough long-term studies on whether it's safe to take melatonin during pregnancy
Because of the lack of research, it’s generally not recommended to take melatonin while pregnant
During pregnancy, you might experience sleep difficulties beyond the typical tossing and turning every night, especially in your third trimester when your belly is larger than the previous two trimesters. Before you were pregnant, you may not have had any concerns about taking a melatonin supplement to help you fall asleep faster. After all, melatonin is a 100% drug-free supplement that can help promote sleep. Now, as a mother-to-be, you might be thinking about taking melatonin to fight your sleep issues during pregnancy. But can you take melatonin while pregnant? And is it safe for both mom and baby?
Your brain naturally produces melatonin as a way of regulating your circadian rhythm, which serves as your internal clock.1 Melatonin plays a key role in regulating the body’s sleep/wake cycle, with the brain producing more as it gets dark (at night) and less as it gets light (in the morning).2 While melatonin doesn’t make you go to sleep, it signals the body that it’s time to sleep, helping you relax and transition to slumber.
In addition to the normal levels of melatonin produced by the brain, women also produce additional melatonin during pregnancy. Both the ovaries and the placenta produce melatonin in high levels in the second trimester and even higher amounts in the third. The body uses melatonin throughout pregnancy.3
Because babies cannot yet produce their own melatonin while in utero, they depend upon their mother’s supply. This explains why the hormone is found in amniotic fluid. In fact, babies don’t begin to produce their own melatonin until they’re about 9-12 weeks old. They continue to rely on the hormone supplied via the mother’s milk.4
Taking Melatonin While Pregnant: Should You Be Worried?
For most adults, melatonin is considered safe to take on a short-term basis, but more research is needed on the long-term effects of melatonin usage. However, when it comes to taking melatonin during pregnancy, there’s been a lack of research on whether melatonin is safe to use in pregnant or breastfeeding women.3
Considering that women produce more melatonin during pregnancy—especially in the third trimester—then taking extra melatonin through a supplement could affect both the expectant mom and her developing baby. The issue is that the medical community just isn’t sure yet what the extent of that impact would be.3
Why? There haven’t yet been enough melatonin pregnancy studies, so there’s no long-term data available. Of the research that’s been done, the studies have either been small or only tested on animals. Based on this limited research, it’s hard to know if the small-study results could be replicated on a larger scale. Similarly, it’s unclear if the results generated from the study of melatonin on pregnant rats would lead to the same results in pregnant women.
Further, because research has not proven whether it’s safe to take melatonin while pregnant there is no standard dosage that exists for taking melatonin during pregnancy. So, even though melatonin is widely available on store shelves, it would be challenging for pregnant women to take on their own because there’s no guidance on how much to take.
Is melatonin safe during pregnancy? Due to a lack of research on melatonin’s effects during pregnancy, it’s not recommended to take melatonin supplements while pregnant.
If you struggle with sleep issues during pregnancy, talk to your doctor. He or she might recommend sleep-promoting strategies such as limiting screen-time before bed, taking a warm bath at night, using relaxation techniques such as meditation or listening to soft music or other lifestyle modifications.
3 McCarthy, R., Jungheim, E. S., Fay, J. C., Bates, K., Herzog, E. D., & England, S. K. (2018). Riding the Rhythm of Melatonin Through Pregnancy to Deliver on Time. Frontiers in Endocrinology, 10. https://doi.org/10.3389/fendo.2019.00616
Lisa Beach is a seasoned journalist whose work has been published in The New York Times, Good Housekeeping, Eating Well, Parents, AARP’s Disrupt Aging, Optimum Wellness, and dozens more. She also writes for a variety of health/wellness-focused brands. Check out her writer’s website at www.LisaBeachWrites.com.
Senior Manager, Medical and Scientific Communications
Melissa is a Registered Dietitian and provides leadership to Pharmavite’s Medical and Scientific Education team. She has over 20 years of experience educating consumers, healthcare professionals, retailers and employees about nutrition, dietary supplements, and overall wellness. Prior to joining the Medical and Scientific Communications team, Melissa launched and managed Pharmavite’s Consumer Affairs department and worked as a clinical dietitian throughout Southern California. Melissa received her Bachelor of Science degree in Nutritional Sciences from the University of Arizona in Tucson, Arizona, and completed her dietetic internship at Veteran’s Hospital in East Orange New Jersey.