Spermicides Spermicidal condoms, foams, or gels kill sperm to help prevent pregnancy. Spermicides that contain nonoxynol-9 (N-9) may cause irritations. These irritations could increase your risk of becoming infected with HIV. The best STI and HIV protection is a lubricated latex condom without N-9. However, a condom lubricated with N-9 is better than no condom at all. The protection you can get from a condom outweighs the risk of using the N-9. Spermicides should only be used for vaginal sex, never for anal sex.