On Birth Control? Watch Out for These Medications

Published: January 6, 2019Updated: August 18, 2022
Which medicines interact with birth control? 9 medications, supplements, and antibiotics that affect birth control pills | SimpleHealth

While birth control is safe to take with most medications, your pills can interact with some medicines. Hormonal birth control releases the hormones estrogen and progesterone, typically produced by the ovaries, into the human body. These hormones are processed by the P450 enzyme system in our livers, so medicines that speed up or slow down this enzyme system will cause the body to metabolize birth control differently.

Your doctor or pharmacist can give you a comprehensive breakdown of which medicines interact with birth control and supplements that affect birth control pills. In the meantime, here’s a comprehensive list of medications, supplements and antibiotics that might affect birth control effectiveness.

1. Antibiotics.

It's a common myth that antibiotics and birth control pills don't mix. However, most antibiotics are absolutely fine to take with hormonal birth control, especially the common ones you might take to treat your acne, sore throat, UTI, or vaginal infection.

There is one caveat: rifampin, an antibiotic used to treat tuberculosis or meningitis. There is evidence that the rifampin antibiotic interferes with the effectiveness of the birth control pill. A typical course of antibiotics for tuberculosis treatment will last 6-9 months, during which time you can use alternate birth control methods such as male or female condoms. Otherwise, ask your doctor or pharmacist any questions about antibiotics and birth control.

2. Anticonvulsants / Mood stabilizers.

If you have epilepsy or bipolar disorder, make sure you speak to your doctor about your medication’s possible interaction with hormonal birth control. Barbiturate medicines commonly used as anticonvulsants, sleep aids, and mood stabilizers have been known to interfere with birth control; these include felbamate, lamotrigine, phenobarbital, and primidone. Other medicines for treating seizures and nerve pain, like oxcarbazepine, carbamazepine, phenytoin, and topiramate, are also known to make birth control less effective. Unfortunately, these negative interactions are a two-way street, meaning they weaken the effects of birth control and birth control weakens their effects too. In any case, if you are on a mood stabilizer or anticonvulsant and want to prevent pregnancy, talk to your doctor about your options.

3. HIV medication.

Some anti-HIV protease inhibitors are known to make hormonal birth control less effective. Some examples of these drugs are nelfinavir, nevirapine, and ritonavir-boosted inhibitors such as tipranavir, lopinavir, fosamprenavir, and darunavir. Luckily, there are some antiretroviral drugs that won’t interfere with the pill’s effectiveness, such as tenofovir, so people with HIV can receive treatment and stay pregnancy-free.

4. St. John’s wort.

St. John’s wort is an herbal supplement that some people take to treat depression, insomnia, or anxiety. St. John's wort is one of the supplements that may affect birth control pills. It can reduce the concentration of progesterone and estrogen absorbed via the birth control pill by up to 15%, altering the hormonal dose enough to cause breakthrough bleeding (bleeding that occurs outside the birth control’s allotted period). While the most recent guidelines do not prohibit St. John’s wort use while on the pill, this supplement should be taken with caution if you want to ensure birth control efficacy.

5. Antidepressants.

To date, science has shown that taking an antidepressant will not disrupt the effectiveness of your birth control. For example, if you’re on the pill and you start taking Prozac or Zoloft, your chances of getting pregnant will not change. That being said, since antidepressants can affect your hormone levels, side effects like an impact on mood or anxiety could be possible (the level of interaction will differ from person to person). One thing to watch out for is if you’re on mood-stabilizing or anti-seizure medication for your depression, which can impact the efficacy of your birth control (see #2 on this list). Every case will be a little different, which is why it’s best to consult with your doctor first.

6. Antifungal medications.

Two kinds of antifungal medications have been known to interfere with the efficacy of birth control—nystatin (used to treat yeast infections) and griseofulvin (used to treat fungal infections like ringworm, jock itch, and athlete’s foot).

7. Anti-anxiety medications.

Not much is known about anti-anxiety medication and birth control interactions; however, some medicines that treat anxiety, sleeping issues, or muscle spasms, such as diazepam and temazepam, are thought to potentially interfere with birth control efficacy.

8. Pulmonary arterial hypertension medication.

If you have pulmonary arterial hypertension (high blood pressure of the lung vessels) and are taking bosentan, you should absolutely consult with a doctor before using birth control. Bosentan decreases the concentration of hormones in the bloodstream, decreasing the efficacy of your birth control and increasing your risk of pregnancy. Bosentan can also cause severe birth defects if taken during pregnancy—another reason to talk to your doctor and make sure your birth control works for you if you have PAH. In our online consultation, we always ask patients about their blood pressure to ensure that doctors can prescribe a medication that is safe and effective.

9. Anti-nausea medication.

Aprepitant is a medication that prevents and treats vomiting and nausea and can interfere with birth control. As a general note, vomiting will negatively impact the effectiveness of oral contraceptives, as the body won’t be able to fully absorb the pill if vomiting occurs within two hours of taking it. If you’re prone to nausea and vomiting, talk to your doctor about your birth control options, as the pill might not be your best choice.  

Looking to try birth control but don't want the in-person office visit? Try SimpleHealth. We make it easy with our online consultation and our easy to access the team of doctors, here for you if you need them. We deliver right to your door and automatically refill your prescription. Best of all? Shipping is free! What are you waiting for?

Birth Control, Simplified

We make getting birth control easy, affordable and way less of a hassle than it's ever been.

We make birth control go from URL to IRL