This study is comparing two different ways to use a medication called Tenofovir (TFV) to prevent HIV. One group will use a product called a *douche*, which is a liquid inserted into the rectum, and the other group will take the medication by mouth. The study is open-label, meaning participants will know which product they are using. Participants will try both products for 8 weeks each, with a break in between. The study looks at how safe the products are, how easy they are to use, and how well they work in the body.
- Participants must be adult men who test negative for HIV.
- Participants must agree to use condoms during the study.
- The study lasts for about 20 weeks with multiple visits required.