Inclusion Criteria:  Cisgender male 18 to 45 years of age HIV-negative Understand written and spoken English condomless anal intercourse with HIV-positive or status unknown partner in past 90 days Meet DSM-5 criteria for methamphetamine use disorder Positive urine toxicology screen for MA metabolites at study entry Negative syphilis screen Negative rectal GC/CT screen (n=20) or Positive rectal GC and/or CT screen (n=20) Able to provide written informed consent and willing/able to complete study visits.  Exclusion Criteria:  Reports current treatment for another substance use disorder Positive test for opioids, cocaine, and/or hallucinogens Treatment for gonorrhea and/or chlamydia infection in past 3 months Presence of a condition that in the opinion of the investigator would compromise the safety of the patient or the quality of the data