PIP: Clinical studies of nonoxynol-9 (N-9) products such as vaginal sponges link the spermicide to vaginal and vulval irritation, even at low doses. Since such irritation may facilitate infection with sexually transmitted diseases (STDs), the chief of the US National Institute of Allergy and Infectious Diseases' STD branch does not recommend that women use the product in their vaginas. Existing products containing N-9 continue to be tested against STDs and HIV, while new ways to prevent STDs and HIV infection are progressing to early clinical trials. New topical, nonirritating microbicides for preventing STDs are promising and will be featured at the May meeting of the American Society of Microbiology as products which could offer women safe, convenient, and almost undetectable protection. Examples include PRO 2000, a naphthalene sulphonate polymer; the "invisible condom," a gel; GEDA Plus, a gel; protegrins; and a "vaginal vitamin," a gelatin suppository. While condom use must continue to be encouraged and STDs treated, placing something into the vagina to either prevent or cure infection is within the realm of existing medical science.