Can you take melatonin while pregnant? Is it safe?

Sleep struggles are common during pregnancy, with sleep disruptions affecting 97% of pregnant women (Chaudhry, 2018). After all, finding a comfortable sleeping position can be difficult as your belly grows, and it seems like as soon as you get comfortable, your compressed bladder alerts you that it’s time to use the bathroom...again. As your due date nears, you may also feel too anxious or excited to sleep. 

In an attempt to get some much-needed shut-eye and knowing that melatonin is a popular sleep aid, you may be wondering if it’s safe to take melatonin while pregnant. Keep reading to learn more about melatonin and why you should check with your healthcare provider before taking it during pregnancy.

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Melatonin is your body’s sleep hormone. The brain naturally produces melatonin in a pattern that sets up your body’s internal clock or circadian rhythm. Melatonin production ramps up in the evening in response to dim light, signaling your body that it’s soon time for sleep (Savage, 2021).

Sometimes, however, sleep doesn’t come so easily. Melatonin supplements are sold over-the-counter and have become a popular natural remedy for sleep troubles. It is not known to cause severe side effects. But, there is limited evidence regarding its safety during pregnancy (Savage, 2021). 

Melatonin supplements contain a synthetic (lab-created) version of melatonin. Keep in mind that melatonin, like all dietary supplements, is not approved by the Food and Drug Administration (FDA). Unlike prescription and over-the-counter drugs, no extensive testing for safety and effectiveness is required for dietary, herbs, or vitamin supplements (FDA, 2020). 

Approximately, 1% of women use melatonin during pregnancy, but it’s considered uncharted territory (Freeman, 2018). There is only limited research on melatonin supplements during pregnancy and their impact on fetal development (Chaudhry, 2018). 

Researchers did not include pregnant women in clinical studies that tested the safety of melatonin supplements, and while most studies have shown that melatonin supplements are generally safe, there is no proof of its safety or risks in pregnant women (Savage, 2021; Chaudry, 2018).

In addition to the lack of evidence, purity issues have been reported with melatonin supplements. A 2017 study found that many melatonin supplements contain extra ingredients or higher amounts of melatonin than what their product labels state. Taking high concentrations of melatonin or consuming unknown ingredients could lead to unexpected side effects, and being pregnant can make you more sensitive or vulnerable to side effects (Erland, 2017).

Limited studies on taking melatonin during pregnancy

Animal studies can help researchers learn about the effects of a medication or supplement during pregnancy. While animal studies do not always reflect what will happen in humans, they can provide some useful clues. Some animal studies have shown that melatonin supplements may increase the risk of problems during pregnancy (Chaudhry, 2018).

A study of pregnant sheep, for example, shows a link between melatonin and decreased birth weight. Further, the sheep that ate large amounts of melatonin went past their expected due dates (González-Candia, 2016). Other research shows that pregnant rats who receive high-dose melatonin supplements have an increased risk of death in their offspring three to six weeks after birth (Singh, 2012). 

On the other hand, some animal studies show that melatonin may have some benefits during pregnancy. Melatonin may have antioxidant or protective effects, but researchers do not yet see these benefits in humans (Chaudhry, 2018; Voiculescu, 2014).

A study in mice suggests melatonin may help prevent early labor or preterm birth that certain bacterial infections can bring on (Dominguez Rubio, 2014). And a lab study of placenta cells shows that reduced melatonin levels might not protect as well against certain factors that lead to preeclampsia. Preeclampsia is a serious pregnancy complication that involves a sudden rise in blood pressure and swelling (Zhao, 2017). But, the medical community needs more studies to test if supplemental melatonin may be helpful in these situations. 

Creating a consistent bedtime routine, with a few added comforts, can help you get better sleep without using medicinal sleep aids during pregnancy. Consider these sleep hygiene tips:

• Cognitive behavioral therapy (CBT) is a safe and proven treatment method for insomnia. Convenient digital options are also available for CBT, which can improve insomnia during pregnancy (Felder, 2020).

• Sleep on your side with the help of strategic pillow placement. You can use extra regular pillows or splurge on a special pregnancy pillow to get comfy and help you avoid sleeping on your back. Back sleeping may reduce blood flow to your baby, especially in late pregnancy (Humphries, 2019).

• Breast tenderness can also make it tough to get comfortable. Wearing a sports bra or a soft-but-supportive sleep bra to bed can be helpful.

• Make sure your bedroom is cool, dark, and quiet. A comfortable mattress, bedding, and room-darkening curtains are usually worth the investment.

• Consider unplugging from your electronic devices at least an hour before bedtime. Blue light from phone or tablet screens can reduce your natural melatonin levels and keep you awake (Wahl, 2019). Instead, try a relaxing pre-bedtime activity like meditating or stretching.

Every pregnancy is different, and there isn’t a one-size-fits-all answer when it comes to melatonin or other supplement use during pregnancy. But generally speaking, it’s best not to take melatonin during pregnancy before checking in with your OB-GYN. More research is needed to determine if melatonin supplements could be unsafe during pregnancy (Chaudhry, 2018).

If you’re pregnant, it’s best to consult a healthcare provider before taking any medications or supplements. They can advise you on what is safe for you to take and a specific dosage to use.

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Every article on Health Guide goes through rigorous fact-checking by our team of medical reviewers. Our reviewers are trained medical professionals who ensure each article contains the most up-to-date information, and that medical details have been correctly interpreted by the writer.

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Current version

October 04, 2021

Written by

Patricia Weiser, PharmD

Fact checked by

Felix Gussone, MD

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About the medical reviewer

Felix Gussone, MD, Ro

Felix Gussone is a physician, health journalist and a Manager, Medical Content & Education at Ro.