Who would have thought that a gel could protect women from HIV? Well, after many failed attempts, for the first time microbocides—compounds that can be applied inside the vagina or rectum to protect against sexually transmitted infections (STIs) including HIV—have successfully achieved their purpose.

In a study conducted by the South Africa AIDS Research Center, researchers discovered that the PRO 2000 vaginal gel cut the risk of contracting HIV by 30 percent. While more research will be done, study leader Salim S. Abdool Karim, PhD, MBChB, director of South Africa’s AIDS research center, stated, “The study, while not conclusive, provides a glimmer of hope to millions of women at risk for HIV, especially young women in Africa.”

The downside: While women were encouraged to use condoms in conjunction with the gel, those who used the gel were less likely to do so. Researchers worry that this type of overconfidence might stop people from using more reliable means of preventing HIV.

Read more about microbicides here.