Effectiveness of COL-1492, a nonoxynol-9 vaginal gel, on HIV-1 transmission in female sex workers: a randomised controlled trial.

Background: Nonoxynol-9 (rINN, nonoxinol-9) is an over-the-counter spermicide that has in-vitro anti-HIV-1 activity. Results of studies of its effectiveness in prevention of HIV-1 infection in women have been inconclusive. We aimed to assess effectiveness of this vaginal gel.