Melatonin can help you fall asleep faster, but while doctors don't recommend long-term use for anyone, people who are on birth control pills should take extra precautions before getting in the habit of reaching for a supplement whenever insomnia strikes.
Savita Ginde, MD, vice president of medical affairs at Stride Community Health Center and former chief medical officer of Planned Parenthood of the Rocky Mountains, explained that melatonin is naturally produced in the pineal gland, the same gland that regulates sex hormones. While there are no definitive studies, "one can propose that taking or adding external melatonin could impact natural cycles, whether it's natural sleep cycles or natural hormonal cycles, such as those that impact ovulation and menstrual cycles and thus affect fertility," Dr. Ginde told POPSUGAR.
Then there's the matter of where and how the body metabolizes melatonin. Heather Bartos, MD, a board-certified ob-gyn, told POPSUGAR that melatonin is metabolized in the liver along with a number of other medications, including birth control pills. "By asking the liver to do double duty, it can lower the effectiveness of the birth control pill," she explained. Dr. Bartos added that certain antibiotics, medications, and supplements can also interfere with the metabolization of birth control, including St. John's wort, an over-the-counter supplement that's commonly used to treat depression.
It's also important to note that melatonin may interfere with certain types of birth control pills more than others, though there hasn't been enough research conducted to determine exactly how and to what extent that's the case. For this reason, Dr. Bartos recommends erring on the side of caution if you regularly take melatonin. "I would switch to a LARC (long-active reversible contraceptive) such as an IUD," she said.
If you're taking melatonin more than "every so often," both Dr. Bartos and Dr. Ginde recommend talking to your doctor to ensure that you're protected from unwanted pregnancy and that your sleep issues are being adequately treated. "If sleep is an issue, don't self-diagnose," Dr. Ginde said. "Talk with your physician about solutions, and if melatonin is part of that plan, you and your doctor can review if and how a particular dose will impact your specific type of birth control."