Nonoxynol-9 is a spermicidal active ingredient available in over-the-counter (OTC) medicines that help prevent pregnancy by killing sperm.
Nonoxynol-9 is approved by the U.S. Food and Drug Administration (FDA) and is safe. It has been found to be most effective when used as directed. Vaginal contraceptive products containing nonoxynol-9 do not protect against HIV, AIDS, or other sexually transmitted diseases. If you do not know if you or your partner is HIV-infected, you should choose another form of birth control.