Overview of Spermicides

Spermicides can be used alone or with vaginal barrier methods such as the diaphragm. Nonoxynol-9, the active ingredient in most spermicides, is combined with a formulation such as gel, foam, cream, film or suppository. Some of these formulations help to disperse the spermicide as well as add lubrication. Nonoxynol-9 is a surfactant that destroys the sperm cell membrane. 

How It Works

Effectiveness depends on consistent and correct use. Always follow manufacturer instructions to ensure correct use of the specific formulation you are using. For spermicides to be effective, manufacturers recommend that spermicides be placed correctly in the vagina no longer than 1 hour before intercourse. The product should be deep in the vagina close to the cervix. In particular, suppositories, foaming tablets and films need adequate time for dissolution and dispersion to be most effective. A new application of spermicide is needed after each act of intercourse. It is recommended to leave the spermicide in place at least 6 hours after the last intercourse.

Using a physical (such as a condom or diaphragm) and chemical barrier, like spermicide, together increases contraceptive efficacy. Also, using emergency contraception to back up spermicides in situations of incorrect or non-use will increase effectiveness. Finally, some people have an allergy or sensitivity to spermicides and may experience skin irritation (if this occurs, try another contraceptive method). With frequent use (twice a day or more) there may be breakdown of the skin, which may increase the risk of infection with HIV. Spermicides do not protect against STI’s. 


Typical use: 71%

Perfect use: 94% 


  • Available without a prescription
  • Can be purchased at pharmacies and supermarkets
  • Can be easily and discretely carried
  • Spermicides can be used to increase the effectiveness of fertility awareness-based methods 


  • High failure rate
  • Possible allergic reaction to nonoxynol-9
  • May provide an unpleasant taste if the couple practice oral sex 


Over the counter product; does not require a prescription (available for purchase through SHCS Medical Services at the Pharmacy, located on the first floor of the UC Davis Student Health & Wellness Center)