Is melatonin safe during pregnancy?

What does the evidence say about melatonin during pregnancy?

1. Taking melatonin supplements during pregnancy hasn't been well studied, and your body already makes more of its own melatonin as pregnancy progresses. 1
2. One older study found that very high daily melatonin doses (75 to 300 mg) lowered the hormone levels needed for conception, showing that large amounts can affect hormones. 1
3. Melatonin is sold as a dietary supplement in the U.S., which means its labeled strength and purity don't have to be verified before it reaches store shelves, and products vary a lot from brand to brand. 1
4. Even outside of pregnancy, there isn't much long-term safety data on melatonin, so checking with a provider before using it is a good idea for anyone. 2

Is melatonin safe in each trimester?

• First trimester. This is the least-studied and most sensitive stage for your baby's development. Providers usually advise against regular melatonin use now.
• Second trimester. Stay cautious here too. Try non-supplement options first, like a consistent bedtime, less light before bed, a cool room, and provider-approved magnesium.
• Third trimester. Researchers have studied melatonin for specific medical situations, like supporting fetal growth, but only in research settings, not as something to try on your own.