Spermicide Ineffective Against STDs

March 6 -- The most commonly used spermicide might be an effective barrier against semen, but is no match for sexually transmitted diseases, new research has determined.

A study published in this week's Journal of the American Medical Association finds that nonoxynol-9 is ineffective in preventing the transmission of gonorrhea and chlamydia.

Nonoxynol-9 has been on the market for 50 years and in the past there was some indication it might also work as a microbicide by killing disease-causing microorganisms. But increasing evidence has proven that wrong. It was recently discovered, for instance, that nonoxynol-9 was not only ineffective in preventing HIV transmission, but that it may actually cause lesions that could facilitate transmission of the disease.

The spermicide remains effective as a sperm-killer, however, and may help prevent pregnancy when used in conjunction with diaphragms or other female barrier methods.

The Final Answer

The JAMA study followed 1,251 high-risk women from the African nation Cameroon who were randomly assigned to use either condoms alone or condoms plus nonoxynol-9 gel. The women were considered to be high-risk because they were being treated for sexually transmitted infections or had symptoms of STDs before they were enrolled in the study.

The group that used both the gel and condoms was found to have no added protection from chlamydia and gonorrhea infections over condoms alone, and, in fact, contracted gonorrhea infections at a 50 percent higher rate.

"It's really the final answer in terms of the continuing accumulation of scientific data showing [nonoxynol-9] in different formulations and doses is ineffective in preventing sexually transmitted disease acquisition by uninfected individuals," says Dr. Ward Cates, president of Family Health Institute, a branch of Family Health International, which conducted the study.

"It was sort of our last hope that it would really help prevent chlamydia and gonorrhea," adds Barbra Richardson, author of an editorial on the new study also appearing in JAMA and research assistant professor of biostatistics at the University of Washington in Seattle. "These investigators showed that no, it doesn't."