Depot Contraception With and Without Lopinavir/Ritonavir

Inclusion Criteria: 1. The ability to understand and sign a written informed consent form, prior to participation in any screening procedure and must be willing to comply with all study requirements. 2. Non-pregnant, non-lactating premenopausal females. 3. No current hormonal contraception (short acting methods eg oral contraceptive pills and patches can be removed at screening) 4. Regular menstrual periods such that DMPA can be administered between days 1-5 of menstrual cycle 5. Between 18 and 45 years, inclusive. 6. Documented HIV-1 infection 7. Must be willing to use a barrier method of contraception to avoid pregnancy throughout the study, and for at least 56 days following completion of the study. 8. CD4 count \> 200 at screening (Note: retesting of screening CD4 count allowed). 9. Clinician and patient happy to delay HAART until week 12 of study 10. Not currently on HAART and eligible to receive LPV/r and Truvada as determined by their primary HIV care provider in accordance with treatment guidelines 11. If history of HAART exposure, no virological failure (prior drug switches allowed if for tolerability/toxicity/convenience of dosing). 12. Agrees not to change regimen, outside the study recommendations, from baseline until end of the treatment period unless this is medically indicated as decided by the treating physician Exclusion Criteria: 1. Any serious or active medical or psychiatric illness which, in the opinion of the investigator, would interfere with subject treatment, assessment, or compliance with the protocol. This would include any active clinically significant renal, cardiac, hepatic, pulmonary, vascular, metabolic disorders or malignancy. 2. Have a body mass index (BMI) \>35 3. Personal history of venous thromboembolism (VTE) or pulmonary embolism (PE) 4. Presence of any current active AIDS defining illness (Category C conditions in the CDC Classification System for HIV 1993) except stable cutaneous Kaposi's Sarcoma 5. Osteoporosis or significant risk factors for osteoporosis (alcohol abuse, long-term anticonvulsants/corticosteroids, BMI less than 18, eating disorder, previous low trauma fracture, significant family history osteoporosis) 6. Conditions for which DMPA is contra-indicated or risks outweigh benefits: 1. Significant multiple risk factors for arterial cardiovascular disease 2. Vascular disease 3. Previous or current venous thromboembolism (VTE) or pulmonary embolism (PE) 4. Ischaemic heart disease 5. Stroke (history of cerebrovascular accident) 6. Headaches migraine with aura, at any age 7. Unexplained vaginal bleeding 8. Gestational trophoblastic neoplasia (GTN) (includes hydatidiform mole, invasive mole, placental site trophoblastic tumour) hCG abnormal 9. Breast cancer (past or current) or strong family history 10. Diabetes nephropathy/retinopathy/neuropathy 11. Other vascular disease or diabetes of \>20 years' duration 12. Viral hepatitis (active) 13. Presence or history of any sever hepatic disease where liver function tests have not returned to normal 14. Cirrhosis (decompensated) 7. Clinically relevant alcohol or drug use (positive urine drug screen, excluding cannabinoids) or history of alcohol or drug use considered by the Investigator to be sufficient to hinder compliance, follow-up procedures or evaluation of adverse events. Smoking is permitted, but tobacco intake should remain consistent throughout the study. 8. The use of disallowed concomitant therapy (See section 5.2). 9. Previous allergy to any of the constituents of the study pharmaceuticals. 10. Exposure to any investigational drug or placebo within 4 weeks of baseline. 11. Any HAART exposure within 6 months of screening for this study (ie participants need to be treatment-naïve or on a treatment interruption for 6 months or more).