After-Sex Gel Could Block HIV Researchers test treatment in monkeys By Matt Cantor, Newser User Posted Mar 13, 2014 10:24 AM CDT 8 comments Comments A study suggests an anti-HIV gel may work after sex. (Shutterstock) (Newser) – A study on monkeys may offer hope for women in the fight against HIV—especially in cases of rape. The study involved a gel that appears effective in blocking HIV in monkeys up to three hours after sex, the New York Times reports. That could mean protection for rape victims as well as women in societies where men refuse condoms, NBC News notes. The study saw monkeys receive vaginal washes of simian HIV. Three hours later, six received the gel, which contains raltegravir, an FDA-approved antiretroviral drug. Others received a placebo. Just one of six monkeys who received the gel became infected; researchers aren't sure what happened in that case. Meanwhile, all of the monkeys who got a placebo became infected. Researchers also tested use of the gel 30 minutes before sex, a scenario which left one of three monkeys infected. An AIDS expert calls the findings "really encouraging," but raises questions about potential human trials. For instance: "How do you justify the use of a placebo?"