Spermicide is a gel, foam, cream, or film that is inserted into the vagina to prevent sperm from reaching an egg. There is also the contraceptive sponge, which is a soft, spermicide-containing, plastic sponge that is inserted into the vagina up to 24 hours before sex. The chemical in spermicide that prevents pregnancy, nonoxynol-9, stops sperm from being able to move. While not harmful, nonoxynol-9 can cause irritation if used more than once a day, increasing risk of STIs. Typical use of spermicide is 79% effective at preventing pregnancy, while typical use of the sponge is 76-88% effective.
 

Spermicide is inserted into the vagina in a similar way as an applicator tampon. It should be placed in the vagina 10-15 minutes before sex, and it only lasts about an hour after insertion. Benefits of spermicide include that it does not require a prescription, can be picked up at most pharmacies, and is hormone-free and inexpensive (with costs as low as 60 cents per use). Drawbacks of spermicide include that it should be used with a condom, must be used every time you have sex, and, with typical use, is less effective than many other contraceptives.