with descovy for prep.s not been studied in people assigned female at birth. talk to your doctor to find out if descovy, the smallest prep pill available, is right for you. in a two-year study, 99.7% of people stayed hiv-negative while on descovy. descovy does not prevent other sexually transmitted infections, so it's important to use safer sex practices and get tested regularly. you must be hiv-negative to take descovy for prep. so, you need to get tested for hiv immediately before and at least every 3 months while taking it. if you think you were exposed to hiv or have flu-like symptoms, tell your doctor right away. they may check to confirm you are still hiv-negative. serious side effects can occur, including kidney problems and kidney failure. rare, life-threatening side effects include a build-up of lactic acid and liver problems. the most common side effect was diarrhea. tell your doctor about all the medicines and supplements you take, or if you have kidney or liver problems, including hepatitis. if