Does Melatonin Make Birth Control Pills Less Effective?

If you rely on oral contraceptives (aka birth control pills) to prevent pregnancy, you want them to be as effective as possible. And if you take melatonin, you might have heard that it could affect your birth control.

But is it true? Can melatonin mess with birth control’s effectiveness? For answers, we turn to Ob/Gyn Emily Freeman, DO.

Does melatonin affect birth control?

“Melatonin doesn’t make birth control pills less effective,” states Dr. Freeman. “But there are some small, older studies that suggest you may experience increased side effects when you take melatonin supplements with oral contraceptives.”

Why might these side effects happen? Birth control pills contain a hormone known as progestin, which is a synthetic (human-made) form of progesterone. And some research from the 1980s shows that progesterone may raise your body’s melatonin levels, perhaps especially during the luteal phase of the menstrual cycle.

“Both progesterone and melatonin promote sleepiness, so the thinking is that adding melatonin supplements on top of birth control pills could make you more likely to experience side effects associated with high doses of melatonin,” Dr. Freeman explains.

But she’s careful to point out that there’s simply not enough data to say whether this is really the case. “From a research standpoint, I would caution against any clinical recommendations from these studies,” she adds.

Side effects of taking melatonin and birth control

Even if you’ve used melatonin before without issues, taking it with birth control pills could raise your overall melatonin levels more than in the past, which may make you feel different.

Possible side effects include:

• Dizziness
• Dry mouth
• Excessive drowsiness
• Headache
• Mood changes or irritability
• Nausea or vomiting
• Vivid dreams or nightmares

And you may not experience any side effects at all — but unfortunately, there’s no way to know ahead of time.

“If you decide to try this combo, do it in a safe place where you can go right to bed if needed,” Dr. Freeman advises. “Don’t try it for the first time when you’re traveling — and never take sleep supplements if you need to drive.”

Oh, and one more thing: Supplements, including melatonin, aren’t regulated by the U.S. Food and Drug Administration (FDA), so there’s no way to know exactly what dosage you’re getting.

“When it comes to melatonin, people take a wide range of doses, from 0.5 milligrams (mg) to 10 mg,” Dr. Freeman says, “but studies show that you may not be getting the dose listed on the label.”

For all these reasons, it’s always best to start with a low dose, like 1 mg or 3 mg.

Tell your provider what you’re taking

The potential side effects between birth control pills and melatonin highlight an important point: Your provider needs a full rundown of everything you take. Some medications and supplements can interfere with birth control pills and make them less effective, including antibiotics and St. John’s wort.

“Tell your provider about all of your medications and supplements, including those labeled ‘natural,’” stresses Dr. Freeman. “Many of them can have unwanted interactions that aren’t listed on the package.”

Your provider can check for any potential issues and help you find safe options. And if you’re having trouble sleeping, don’t try to self-medicate at home. Your provider can help with that issue, too.

“Many different factors can affect your ability to sleep, and melatonin may not be the answer,” she emphasizes. “You may need to see a sleep specialist, who can determine the root cause of any sleep issues. That’s the safest and most effective way to get the rest you need.”