Spermicide is inserted into a woman's vagina to kill or disable sperm thus preventing a sperm from fertilizing an egg. Spermicides come in many different forms: foam, jelly, cream, film, and suppositories. Most use the chemical nonoxynol-9 against sperm. Spermicides provide lubrication and can be used with other methods of birth control. They are most effective when used consistently and correctly with a barrier method of birth control, like a condom. Spermicides are 71-82% effective as birth control. Used alone, spermicide does not protect against HIV/AIDS.