I am on the birth control patch (Twirla®) but I got sick and my doctor prescribed me with antibiotics (specifically Cefdinir) to help treat it. Don’t antibiotics cancel out my birth control? If I’m sexually active, am I at risk of pregnancy?

young adult applying contraceptive patchThank you for your question! The concern that antibiotics cause birth control to be less effective is a common, false myth. Most common antibiotics do not affect hormonal birth control at all. The only antibiotics with the risk of interacting with your birth control are rifampicin and rifabutin, medications used to prevent or treat meningitis, tuberculosis, and other bacterial (non-viral) infections. Your birth control will continue to prevent pregnancy while you take your antibiotics.

As always, we recommend using a condom when having PIV (penis-in-vagina) sex for added protection against both pregnancy and sexually transmitted infections. If you have more questions, reach out to your health care provider (HCP)!


Our health guides are developed through a systematic, rigorous process to ensure accuracy, reliability, and trustworthiness. Written and reviewed by experienced healthcare clinicians from Boston Children's Hospital, a Harvard Medical School teaching hospital and consistently ranked as a top hospital by Newsweek and U.S. News & World Report, these guides combine clinical expertise, specialized knowledge, and evidence-based medicine. We also incorporate research and best practices from authoritative sources such as the CDC, NIH, PubMed, top medical journals, and UpToDate.com. Clinical specialists and subject matter experts review and edit each guide, reinforcing our commitment to high-quality, factual, scientifically accurate health information for young people.