Spermicides & Microbicides

What are microbicides?

Microbicides are products that are being developed for use either vaginally or rectally to reduce the transmission of HIV and/or STIs. Research has been conducted for the last decade to develop microbicides in many forms including gels, creams, suppositories, films, a sponge or a vaginal ring. Some microbicides will also offer contraceptive benefits. Microbicides are not available yet, but the public can expect to find a microbicide on the market in the next 5 years.

Is Nonoxynol-9 a microbicide?

Nonoxynol-9 (N-9) is the active ingredient found in many over-the-counter contraceptive gels, creams, foams, films, and suppositories. N-9 functions by immobilizing and killing sperm that are ejaculated into the vaginal canal. Because it kills sperm, scientists initially believed that it would also act as a microbicide, killing common bacterial STIs such as chlamydia and gonorrhea as well as the HIV virus. However, there have been inconsistent findings, with some studies reporting N-9 STI protection as high as 40% to 50% while other studies found no statistically significant protection at all.

Because of the belief that N-9 offers protection against certain STIs and HIV, many couples use N-9 spermicides for anal sex, instead of, or in addition to its contraceptive use for vaginal sex. However, a 2000 study found that N-9 spermicides irritated the vaginal and rectal lining and actually increased a recipient's exposure risk to an STI or HIV (Vaginal Microbicides, an update. XIII World Conference on HIV/AIDS. Durban, South Africa, July 12, 2000). If a couple using a product with N-9 should notice any genital irritation, they should discontinue use, try a spermicide with a lower amount of N-9 or try a spermicidal gel or cream with octoxynol, an alternative to N-9.

Links you can use

To learn more about N-9 and microbicide research and development, you can visit:

CDC's Statment on the Durban, South Africa N-9 study

Program for Appropriate Technology in Health's Microbicide Campaign

The Alliance for Microbicide Development

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