Do certain medications make birth control less effective?

Yes! Taking certain medications together can reduce their effectiveness, or cause unexpected side effects. The pill usually contains the female sex hormones estrogen and progestin. They stop eggs from leaving the ovaries, thereby preventing pregnancy. However, some medications don’t let the hormones do their job, and if you take them at the same time as your birth control, you may not have the protection you think you do. This is why if you intend to get on the pill, it is very important to know what these medications are.


For the most part, you don’t have to worry about taking antibiotics while being on the pill. So far, the only antibiotic that studies show interferes with birth control is a drug used to treat tuberculosis, which causes irregular periods and raises the risk that you may get pregnant even if you use your birth control the right way.

Apart from this medication, you’re safe to take birth control pills at the same time as antibiotics without also using a back-up method.

Anti-HIV Drugs

Some meds that treat HIV may interfere with the pill. Talk to your doctor about what medicine is best for you.

Anti-Fungal Medications

Some medication used to treat skin infections like athlete’s foot and jock itch. While experts believe the risk of anti-fungal meds affecting your birth control pills is low, you should check with your doctor if you happen to be using the ones mentioned above.

Anti-Seizure Drugs

Some medications increase the breakdown of the hormones in birth control pills which could make them less effective. It is recommended that you use another form of birth control (like an IUD, a diaphragm, or a condom) if you take anti-seizure medication.


Some medicines prescribed for depression can theoretically alter hormone levels. Antidepressants may lower the number of hormones (estrogen and/or progestin) circulating in your body, which can compromise the pill’s effectiveness. This can vary significantly from person to person, so a decrease in the number of circulating hormones may equal a bigger drop in the pill’s effectiveness for some women than for others. On the flip slide, research has also suggested that the estrogen in the pill may decrease the effectiveness of the antidepressant.

To avoid any possible drug interactions, make sure you talk to your doctor if you’re currently being treated with a specific antidepressant and wish to be on the pill at the same time.

Pulmonary arterial hypertension (PAH) medication

If you have pulmonary arterial hypertension (high blood pressure of the lung vessels), you should absolutely consult with a doctor before using birth control. This type of medication decreases the concentration of hormones in the bloodstream, decreasing the efficacy of your birth control and increasing your risk of pregnancy. It 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.

Herbal Remedies

A number of these over-the-counter herbal remedies don’t mix well with birth control pills. The most important one you should avoid is:

St. John’s wort – Some people use it to treat mild to moderate depression and sleep disorders. A study shows that women who took birth control pills and St. John’s wort at the same time had higher rates of breakthrough bleeding and an increased breakdown of estrogen in their bodies, signs that the contraceptives might not work as well as they should.

Other herbal remedies that may affect how well your birth control pills work are:

  • Saw palmetto – some people have tried it for hair loss.
  • Alfalfa – this is used for kidney, bladder, and prostate problems.
  • Garlic pills – some people take these for high blood pressure, high cholesterol, and other heart and blood diseases.
  • Flaxseed – this is used for digestion problems like severe constipation and irritable bowel syndrome.
  • Soy isoflavones – these are natural substances obtained from the soybean plant which claim to reduce the intensity of menopause-related hot flashes and to help maintain strong bones.


The birth control pill is an extremely reliable form of contraception. However, like most medications, its effectiveness can be reduced when consumed together with certain types of medication. If you intend to get on the pill and are currently taking any of the medications listed above, you can arrange a consultation with one of our licensed physicians to discuss how your current medication may affect the effectiveness of the pill.

This is why at Ease, we ask you if you are currently taking any of the above medications, or any other medication that might reduce the effectiveness of the pill. That way, we can help you plan ahead, and make sure that we prescribe the right type of birth control to suit your circumstances.

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