Heterosexual transmission of HIV presently accounts for the vast majority of new HIV infections worldwide. Currently the condom is the only method available that has been shown to be effective against HIV and other sexually transmitted diseases (STDs). However, women who are at the greatest risk for acquiring HIV are often unable to negotiate condom use. Therefore, it is important that effective female-controlled barrier methods, such as topical microbicides, be made available to women. BufferGel has sufficient buffer capacity to acidify twice its own volume in human semen, which inactivates STD pathogens, including HIV. Unlike most other topical microbicides, BufferGel is non-detergent so it should not cause genital irritation and lesions. The safety and acceptability of BufferGel still need to be studied more carefully.