You might have heard that there are some supplements — we're talking about St. John’s wort — that should be avoided while using hormonal contraceptives. With an estimated 3 million Americans using the supplement melatonin as a sleep aid as of 2012, you might also be curious about the interactions between hormonal birth control and that particular supplement. If that's you, you've come to the right place.
In this piece, we’ll shed more light on the following takeaways:
- Melatonin is a hormone, not a vitamin, that helps regulate your 24-hour internal clock (aka your circadian rhythms) and sleep. The body produces and releases more melatonin when it’s dark and then supply decreases when it's light.
- Although there’s been limited research on the interaction between melatonin supplements and contraceptives, there’s no data to suggest that melatonin interferes with the effectiveness of birth control.
- However, use of melatonin alongside birth control might cause an additional sedative effect and increase possible side effects of melatonin (headache, dizziness, drowsiness).
Let's dive into the details.
First things first: What's melatonin?
Melatonin, sometimes referred to as a “sleep hormone,” is a key player in regulating your sleep schedule; it helps you drift off at night and wake up in the morning. Although it’s produced in the body, it's the supplemental form that’s often discussed — marketed as a key ingredient in sleep aids and beauty-rest products.
More recently, researchers have also been looking into the effects of melatonin on COVID-19. Although a relatively new subject with no official findings, there are several randomized controlled trials (the gold standard in clinical research) in Spain and Iran currently evaluating whether melatonin might be helpful for people with COVID-19. (We're eager to see results here soon.)
Interesting. So… is melatonin a supplement or produced in the body?
Both! Natural melatonin is produced in the body by the pineal gland in the brain, then released into the bloodstream. The body increases melatonin production in the evening, with night-time levels said to be at least 10-fold higher than daytime concentrations. Levels peak in the middle of the night, between 2am and 4am, and then decrease until morning when the secretion of melatonin ceases.
Melatonin is also available as a natural or synthetic supplement (FYI, vegans: the natural version is made from the pineal gland of animals). It’s classified as a dietary supplement, which means it’s less strictly regulated by the Food and Drug Administration (FDA) and is available without a prescription.
Although the consensus is that melatonin supplements are safe for most people, it’s important to note that there are no official recommendations or guidelines for the amount of melatonin to take. In fact, a study of 31 different melatonin supplements found that the actual melatonin content often varied from the content listed on the label.
Does melatonin affect birth control?
To date, there’s been limited and conflicting research on the interaction between melatonin supplements and contraceptives. However, there’s no data to suggest that melatonin interferes with the effectiveness of birth control. If anything, birth control might actually exacerbate the effects of melatonin, according to Mayo Clinic.
If you’re using hormonal birth control and interested in trying melatonin as a sleep aid, consider speaking with your healthcare provider first — something that's always recommended before taking supplements. They might recommend you explore other sleep-promoting methods:
- Creating a quiet, cool, and dark sleep environment.
- Avoiding caffeine, alcohol, and large meals before bedtime.
- Exercising during the day — not right before bed.
- Removing electronic devices (phones, TVs, computers) from your sleep environment.
How are melatonin and birth control related?
Melatonin shouldn’t affect your birth control, but there is a noteworthy connection between the two, specifically birth control that contains progestin. As a reminder, progestin is a synthetic form of progesterone — a hormone that helps regulate the menstrual cycle and promote pregnancy and is found in most hormonal contraceptives.
Some birth control contains only progestin — the minipill, hormonal intrauterine device (IUD), contraceptive implant, and most birth control shots — while the pill, patch, and ring contain both progestin and estradiol.
So, what's the connection between melatonin and progestin?:
- A 2019 observational study published in Gynecological Endocrinology found that among 108 women taking hormonal contraception, low doses of progestins can affect various aspects of sleep, with the greatest change among people using the vaginal ring.
- Another small study suggested a correlation between melatonin and progesterone among people taking triphasic contraceptive pills (these pills contain three different doses of hormones so that the formulation changes weekly throughout your cycle): Melatonin levels significantly increased with an increase in the dose of progestin. However, more research is needed to show causation.
Although this research is pretty limited, this relationship between progestin and melatonin might be the reason birth control can exacerbate the effects of melatonin supplements: more progestin means higher levels of melatonin are already in the body.
What other supplements have interactions with birth control?
Any type of hormonal birth control will come with a list of medications and conditions that could cause a potential interaction. One supplement that's on all of them is St. John’s wort, which is used to help combat symptoms of depression, anxiety, and insomnia. Research suggests that it can potentially decrease the effectiveness of hormonal birth control, resulting in irregular bleeding or breakthrough bleeding which can increase risk of unplanned pregnancy.
You might have also heard about another plant-derived supplement and an adverse relationship with hormonal birth control: soy isoflavones. OB-GYN and Modern Fertility medical advisor Dr. Eva Luo, MD, MBA, FACOG says this is unlikely to be the case. "Soy isoflavones have substances very similar to estrogen and are much, much weaker than human estrogen," she explains. "Studies are conflicting — with some saying that taking isoflavones have reduced hot flashes and some studies saying there was no effect at all. Given how weak they are in effect, there's likely no clinical impact on hormonal birth control."
We've gotten a lot of questions about hormonal birth control and prenatal vitamins in the Modern Community: Is there an interaction there? "There should be no concern that prenatal vitamins interact with birth control," says Dr. Luo. "None of the materials in prenatal vitamins are of concern."
Before taking any supplements, whether or not there's a potential interaction with birth control, it's always a good idea to seek out medical advice from your healthcare provider.
The bottom line
Your body intuitively knows to produce more melatonin when it’s dark (especially between 2am and 4am) and to decrease the supply when it's light. Melatonin is also available in supplemental form to help with trouble sleeping, jet lag, and surgery-related anxiety. As it stands, taking melatonin won’t affect your birth control, but check with your healthcare provider just to be extra safe (which is important to do before taking any supplement).
This article was medically reviewed by Dr. Eva Marie Luo, MD, MBA, OB-GYN at Beth Israel Deaconess Medical Center and Clinical Lead for Value at the Center for Healthcare Delivery Science at Beth Israel Deaconess Medical Center.