6 Medications That Can Affect Birth Control’s Effectiveness

When you're on the birth control pill, you want to make sure the contraceptive is as effective as possible, which is why it's important to be aware of any possible negative interactions. Although most of the time there isn't much of an issue, there are a number of medications that can affect birth control effectiveness. Whenever you're prescribed something, it's always worth telling your doctor if you're on the pill, but you can also keep in mind the specific medications that may cause an issue in case you ever need them down the line.

"Many patients ask me if when taking birth control along with other medication, are they more at risk of side effects or complications," family physician Navya Mysore, MD, tells Bustle. "This is not necessarily the case. I worry more that the medication they are on could reduce the efficacy of their birth control medication. Hormones in different forms of birth control are all metabolized in the liver, where often many other medications are also broken down. The increased production of liver enzymes by other medications a patient is taking may interfere with possible hormone absorption."

When in doubt, you should always consult with your doctor about your risk of interference when it comes to different medications and your contraceptives, and discuss other forms of contraception that you are comfortable with in the meantime. Here are six medications that can mess with your birth control, according to experts.

1Certain Antibiotics

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Thankfully, you don't have to stress too much next time you get something like strep throat — most antibiotics pose no problem when taken with birth control. However, there is one antibiotic, Rifampin (a tuberculosis antibiotic) that has been studied and known to interfere with birth control. "Rifampin can cause irregular periods, and despite birth control, there is still the risk you can get pregnant," says Dr. Mysore. "Other antibiotics may also interfere with birth control, so as a caveat, we recommend a secondary form of protection."

2Anti-HIV Drugs

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Certain types of anti-HIV drugs can affect your liver metabolism, therefore making your birth control less effective. "There is a list of HIV medications that absolutely interfere with birth control and some that do not," says Dr. Mysore. In these cases, ask your doctor which medication is best for you.

3Anti-Fungal Medications

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Again, anti-fungal medications can affect the way your liver metabolizes your birth control. "Similarly to the family of most antibiotics, it's unknown how much it reduces birth control efficacy, but we recommend using a back up form of birth control," says Dr. Mysore. According to WebMD, the two main types of anti-fungal medication to watch out for are griseofulvin (Gris-PEG) and ketoconazole.

4Anti-Seizure Drugs

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Some anti-seizure medications (AEDS) can increase the livers ability to break down the hormones in birth control pills, which can lead to the pill decreasing in effectiveness. "It's important that patient's taking these medications should use another form of birth control like the IUD, implant, condoms etc.", says Dr. Mysore

5Modafinil (Provigil)

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"Modafinil is a medication that is used as a stimulant and can reduce the efficacy of birth control," says Dr. Mysore. People who take this medication typically have sleep disorders such as narcolepsy or sleep apnea. Alternative contraception is recommended while on this medication.

6St. John's Wort

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St. John's Wort is an herbal remedy that people use to treat depression or sleep disorders. However, it can cause a decrease in estrogen levels, which can affect your likelihood of getting pregnant. "It can cause break through bleeding when on birth control, and this can reduce the efficacy of birth control," says Dr. Mysore.

If you do get prescribed these medications, let your doctor know you're on birth control, and be sure to use another form of contraceptive.