This pilot study is a longitudinal cohort study of approximately 100 MSM, with a prospective follow-up period of 1 year for each participant. MSM will be recruited through community events, venues where MSM are known to congregate, online, and by participant referral. Following consent, a baseline visit will include a self-administered baseline survey, a clinical exam including an assessment for circumcision and STIs, and testing for HIV and other STIs, creatinine, AST/ALT and phosphorus levels, and drug screening.