How long after taking antibiotic is birth control effective

Top things to know

Most antibiotics will not interfere with your hormonal birth control method
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Only rifamycins, including rifampin, will make your birth control less effective
If you are prescribed rifampin, be sure to use back-up protection like condoms or abstain from sex

I’m on hormonal birth control. Can I get pregnant if I take antibiotics?

In most cases, no, as long as you continue to use your hormonal contraception as prescribed you are safe from pregnancy even if you are on antibiotics.

It is a myth that all antibiotics will interfere with the efficacy of your birth control pill.

There is however, one class of antibiotics that is the exception: rifamycins (1).

What do I need to know about Rifamycins?

Rifamycins are a class of antibiotics. The most commonly prescribed rifamycin is known by the name rifampin. (Other types of rifamycins include rifapentine, rifabutin, and rifaximin.) Rifampin is not prescribed very commonly in the United States.

Rifamycins, are most commonly prescribed for the treatment of mycobacterial infections, including tuberculosis (1), or for treating travelers’ diarrhea caused by E. coli (2).

Rifampin can sometimes be used in combination with other antibiotics to treat other bacterial infections too (1). (Fun fact about rifampin: one of the side effects is that it may turn your urine, tears, saliva, and sweat a red color (3).)

Rifampin, can speed up the liver’s ability to break down molecules and medications, including hormonal birth controls, which are processed continually through the liver (3).

For this reason, anyone taking any form of hormonal contraceptive, like the pill, patch, ring, mini-pill, and the implant, who is prescribed rifampin treatment should note that their hormonal contraceptive will not be as effective, and may increase their likelihood of becoming pregnant (3-5).

Rifampin does not interact with other forms of birth control, such as the contraceptive shot, the copper IUD, and the hormonal IUD, meaning that you can continue to use these types of contraception while undergoing rifampin treatment (4,5).

What if my healthcare provider prescribes rifampin for me?

If your healthcare provider does prescribe rifampin to you, be sure to let them know if you are using a hormonal contraceptive.

Unless otherwise stated by your healthcare provider, you can still continue to take your pills as usual every day. However, during this time, it’s important to use non-hormonal birth control methods, like external or internal condoms, or abstain from sex as backup protection during rifampin treatment (3).

If you use birth control pills, consider following the recommendations for what to do if you miss two or more pills:

Continue to use these non-hormonal backup methods for 7 days after you stop taking rifampin, provided you still have 7 hormone-containing pills left in your pack
If there are fewer than 7 hormonal pills left in the pack after you stop taking rifampin, skip the hormone-free pills and start a new pack, but still continue to use back-up contraception for the first 7 pills of the pack (6).

If you are using another form of hormonal contraceptive, like the patch or ring, speak to your healthcare provider.

Things to keep in mind, when you’re sick

Even if you aren’t on rifampin, being ill is hard on the body and mind. If you are sick, it’s easy to lose track of time and responsibilities, and you might forget to take your pill (or other daily medication). Use Clue to set up pill reminders, or task a family member, partner, or friend, to help remind to make sure to take your contraceptive pill daily at the same time.

Use the Clue app to set up daily pill reminders.

an image of 3 mobile
screens of the Clue app

I was watching tv, and they said that if your on birth control and taking antibiotics the birth control will stop working. Im on the pill right now, and I’ve had to start taking antibiotics because of a kidney infection. Is it true that the birth control will stop working? and if it does how long after I stop taking the antibiotics will the birth control work again?

No. You can take the antibiotic you’ve been prescribed for your kidney infection and your birth control pill will keep protecting you. Only one antibiotic is known to make the pill less effective. That is rifampin, a special medication used to treat tuberculosis. The brand names include Rifadin and Rimactane. Other antibiotics do not make the pill less effective. There are medications that can interact with the pill and decrease its effectiveness. Also, the pill can decrease or increase the effectiveness of some medications. That’s why it’s important to be honest with your health care provider and let her or him know if you’re on the pill. Always let providers know about all the drugs and medications you take — prescription, over-the-counter, recreational — before they prescribe anything new for you.

Tags: birth control, the pill, antibiotics