Researchers have launched an early human trial of an HIV-preventing vaginal ring that requires replacement every three months instead of every month, as is the case with the ring currently up for regulatory approval. The Phase I study is testing the safety of the ring, which contains the antiretroviral dapivirine, as well as analyzing how the body processes the drug. The study will also gauge how eager women are to use such an HIV prevention method and how well the 50 or so 18- to 45-year-old study participants adhere to the instructions for its use. The women are randomized to receive a vaginal ring designed for three months of use that contains either 100 milligrams or 200 mg of dapivirine or a one-month ring containing 25 mg of the drug. The results of the trial are expected in late 2018.