An FDA-approved drug can prevent HIV infections, but critics have worried that having such a fallback pill can promote unsafe sex and cause HIV infections to rise. A new study proves them wrong. Reporting in JAMA Internal Medicine, researchers show that providing PrEP to men who have sex with men dropped their rates of HIV dramatically. In the study, conducted at two clinics treating sexually transmitted diseases and a community health center in three different cities, 437 men and transgender women took PrEP, which consists of emtricitabine and tenofovir (together called Truvada), for nearly a year. Only two became HIV positive, but both showed extremely low blood levels of the drug, suggesting that they took only about half of their required doses.

Rates of STIs, while high, did not increase during the study period while the participants were taking PrEP. In other words, the drug did not make users more promiscuous or more reckless about their risk.

But PrEP continues to suffer from an image problem. In the months and years after it was approved, even those in the gay community, perhaps skeptical of its too-good-to-be-true promise, began denigrating those who took advantage of the drugs, labeling them Truvada whores. Well respected and early pioneers in AIDS advocacy were equally leery, seeing PrEP as a dangerous cancer that could eventually undo all the laborious work they had put into educating people about the disease and warning them about the unsafe behaviors that promote HIV. Read more via Time