Pharmacokinetics and Pharmacodynamics of DMPA With HIV PrEP

Inclusion Criteria: * Women aged 18-45 at screening * In general good health and without any clinically significant systemic disease by history and per investigator judgement * HIV negative at screening * Heterosexually abstinent, consistent use of condoms, or female or male partner sterilization * Currently having regular menstrual cycles (defined as cycles lasting 21-35 days by participant report) * Agree not to participate in any other clinical trials involving drugs or medical devices during the study period * Willing to comply with the study protocol Exclusion Criteria: * Currently or recently pregnant or breastfeeding (defined as pregnancy or breastfeeding in the last 3 months) * Desiring pregnancy in the next 9 months * Use of copper intrauterine device or other method of hormonal contraception * Status post hysterectomy and/or bilateral oophorectomy * Positive test for Hepatitis B surface antigen at screening * Positive for Neisseria gonorrhea, Chlamydia trachomatis, or Trichomonas vaginalis at screening * Positive syphilis screening test at screening * Symptomatic bacterial vaginosis, defined as vaginal symptoms with Nugent score ≥ 7. (If symptomatic bacterial vaginosis is treated at screening and asymptomatic at enrollment, the participant may enroll.) * Renal impairment (defined as creatinine clearance \<60 ml/minute) * Known bleeding disorder * Daily use of NSAIDs * Systemic use in the last two weeks or anticipated use during the study of any of the following: corticosteroids, antibiotics, anticoagulants, antifungals, antivirals, antiretrovirals, or other drugs known to prolong bleeding and/or clotting, * Use of DMPA in the 6 months prior to screening * Use of other hormonal contraception (including any contraceptive pill, patch, ring, implant, or levonorgestrel intrauterine device) in the 28 days prior to screening. * Surgery requiring inpatient admission, or any abdominal surgery \<30 days prior to enrollment * Recreational or non-medical injection drug use in the 12 months prior to screening * In a sexual relationship with a partner known to be HIV-positive or at high-risk of HIV (e.g. known recreational injection drug user, incarcerated in the 12 months prior to screening, etc.) * Has any other condition that, in the opinion of the investigator, would preclude informed consent, make study participation unsafe, or complicate the interpretation of the study outcome data, or otherwise interfere with achieving the study objectives