The present disclosure relates to compositions and methods for contraception that also enhance the efficacy of microbicides. Such compositions serve the dual purpose of preventing pregnancy and lessening the risk of spreading sexually transmitted diseases. More specifically, the compositions and methods relate to syngergistic contraceptive microbicide and antiviral compositions comprising a combination of a contraceptive microbicide and an antiviral agent in an acidic carrier that enhances the efficacy of both the contraceptive microbicide and antiviral agent.