HIV prevention advocates have long hoped for a microbicide. If an odorless vaginal gel could kill HIV before it enters the bloodstream, after all, it would allow women to protect themselves during sex—without their partners’ knowledge. If the imbalance of power between men and women fuels high HIV rates among women, can a gel change the balance? Real Health asked Anna Forbes, deputy director of the Global Campaign for Microbicides.

“Women’s empowerment is complex, involving many factors,” Forbes says. “Microbicides alone are not the key to stopping the epidemic, but they are a key.” They will provide tools for women who want to take control.

“It’s heartbreaking,” Forbes says, “to see a woman getting her life together—leaving a violent relationship, for example—and ending up with HIV because she didn’t have the ability, while on the path to empowerment, to protect herself.”

“There are about 50 products in development,” Forbes says, “based on interesting stuff like an extract of tobacco juice.” (Many substances inhibit HIV in test tubes but are not usable by humans.) Then there’s the experimental “molecular condom”—a gel activated by semen to spread into a firm barrier. To date, just one compound, PRO 2000, has shown any promise in human trials.

Gels that include HIV drugs may be most effective. But they have issues, Forbes says—including the risk of provoking drug resistance. Compounds that don’t rely on HIV meds to block transmission will have an additional advantage: They will be available over the counter, no prescription needed.

Some trials have shown that using a microbicide correctly— and consistently—can be a challenge. Not to worry, Forbes says. “Women aren’t stupid. We can learn to insert products and devices—and remember to do that—when it’s something we feel is important.” Using a microbicide will be like using contraceptives, she says: If you really don’t want to get pregnant, you don’t forget the device or pill.