We evaluate the impact of a health information intervention implemented through mobile phones, using a clustered randomized control trial augmented by qualitative interviews. The intervention aimed to improve sexual health knowledge and shift individuals towards safer sexual behavior by providing reliable information about sexual health. The novel technology designed by Google and Grameen Technology Center provided automated searches of an advice database on topics requested by users via SMS. It was offered by MTN Uganda at no cost to users. Quantitative survey results allow us to reject the hypothesis that improving access to information would increase knowledge and shift behavior to less risky sexual activities. In fact, we find that the service led to an increase in promiscuity, and no shift in perception of norms. Qualitative focus groups discussions support the findings of the quantitative survey results. We conclude by discussing a potential mechanism explaining the counterintuitive findings.