Can medicines affect how the progestogen only pill works?

Some medicines make the progestogen only pill less effective (including those used to treat epilepsy, HIV and TB, and the herbal medicine St John’s Wort). Read the information that comes with your medicine, and if you're unsure, ask our clinicians.

The antibiotics rifampicin and rifabutin (which can be used to treat illnesses including tuberculosis and meningitis) can reduce the effectiveness of the progestogen only pill.

Other antibiotics do not have this effect. If you are prescribed rifampicin or rifabutin, you may need additional contraception (such as condoms) while taking the antibiotic and for 28 days after.

Always tell your doctor that you are taking the progestogen only pill if you are prescribed any medicines.