Researchers from the U.S. and Lima, Peru, who used consumer marketing techniques to gauge acceptance of pre-exposure prophylaxis (PrEP) among high-risk groups in Lima, found that study participants were generally supportive of the therapy but that out-of-pocket costs had the greatest impact — even more than the drug’s effectiveness — on their willingness to use it. Participants also expressed concerns over sexual risk disinhibition, the potential stigma associated with PrEP use and mistrust of health care professionals.