Spermicide - Types and Effectiveness

Types and Effectiveness

The most common active ingredient of spermicides is nonoxynol-9. Spermicides containing nonoxynol-9 are available in many forms, such as jelly (gel), films, and foams, but not recommended by the CDC. Spermicides cause irritation and according to the CDC, studies have shown that spermicides increase the risk of HIV. Contraceptive Technology states that spermicides have a failure rate of 18% per year when used correctly and consistently, and 29% under typical use.

Menfegol is a spermicide manufactured as a foaming tablet. It is available only in Europe.

Octoxynol-9 was previously a common spermicide, but was removed from the U.S. market in 2002 after manufacturers failed to perform new studies required by the FDA.

The spermicides benzalkonium chloride and sodium cholate are used in some contraceptive sponges. Benzalkonium chloride might also be available in Canada as a suppository.

The 2008 Ig Nobel Prize (a parody of the Nobel Prizes) in Chemistry was awarded to Sheree Umpierre, Joseph Hill, and Deborah Anderson, for discovering that Coca-Cola is an effective spermicide, and to C.Y. Hong, C.C. Shieh, P. Wu, and B.N. Chiang for proving it is not.

Lemon juice solutions have been shown to immobilize sperm in the laboratory, as has Krest Bitter Lemon drink. While the authors of the Krest Bitter Lemon study suggested its use as a postcoital douche, this is unlikely to be effective, as sperm begin leaving the ejaculate (out of the reach of any douche) within 1.5 minutes of deposition. No published studies appear to have been done on the effectiveness of lemon juice preparations in preventing pregnancy, though they are advocated by some as 'natural' spermicides.

Lactic acid preparations have also been shown to have some spermicidal effect, and commercial lactic acid-based spermicides are available. However, no published studies on the effectiveness of lactic acid in preventing pregnancy appear to have been done since 1936. Thomas Moench, a former assistant professor of medicine, has said that research into acids as spermicides has "pretty much been abandoned."

Extractives of the neem plant such as neem oil have also been proposed as spermicides based on laboratory studies. Animal studies of creams and pessaries derived from neem have shown they have contraceptive effects, however trials in humans to determine its effectiveness in preventing pregnancy have not yet been conducted.