What is a spermicide?

A spermicide is a substance that is effective in killing sperm. There are two spermicides available in the United States, nonoxynol-9 and octoxynol. These are available as a foam, cream, jelly, suppository, film, and spermicidal condom.

How does it work?

The spermicide works with a condom or diaphragm making them more effective. The spermicide kills any sperm that may happen to leak out in case the condom leaks or breaks. The spermicide also kills any sperm that manage to break the seal of the diaphragm.

Does it prevent STD transmission?

Spermicides have been found to kill the organisms that cause gonorrhea, genital herpes, trichomonas, syphilis and AIDS in a laboratory environment; however, this does not guarantee that it will kill these organisms in the real world. There is still great debate as to whether spermicides decrease or increase the risk of some STD transmission. Therefore, one must be very careful in choosing one's sex partners, and be aware of the behavioral characteristics that put one at increased risk of transmission.


Some spermicide products are marketed for use alone, without a condom or diaphragm, such as the foam or suppository. The failure rates of spermicide use in this way is nearly impossible to predict, and results ranged from 0% to 50%. The most important way to improve the effectiveness of spermicides is to use them consistently and use them with a condom or diaphragm. For the perfect user, the failure rate for condoms alone is 3%, for spermicide alone is 6%, but with use of both condom and spermicide the failure rate is 0.01%.

Do you need a prescription for spermicide?

No, they can be purchased over the counter at pharmacies, clinics, grocery stores etc. Care must be taken that when purchasing, a lubricating jelly isn't mistaken for a contraceptive gel.

Risk Factors

Some people have noted an allergy to the spermicide and temporary skin irritation. Aside from that, no systemic side effects have been reported.