The Tolerability of, and Adherence to, Dolutegravir With Co-formulated Tenofovir-emtricitabine for HIV Non-occupational Post-exposure Prophylaxis

Inclusion Criteria: 1. Man who has sex with men 2. Age at least 18 years 3. Potential HIV exposure following: * receptive anal intercourse with a source known to be HIV-infected; or * receptive anal intercourse with a source of unknown HIV status; or * insertive anal intercourse with a source known to be HIV-infected 4. Able to provide written, informed consent 5. Able to commit to the study visits Exclusion Criteria: 1. Non-sexual exposure 2. Exposure occurring during sex between a man and a woman 3. HIV infection diagnosed on baseline testing (antibody, Western blot, proviral DNA) including indeterminate serology consistent with possible primary HIV infection 4. Use of any medication contra-indicated with DTG, FTC or TDF 5. Use of any medication that effects the concentration of dolutegravir and / or concomitant drug including: oxcarbazepine, phenytoin, phenobarbital, carbamazepine, rifampicin, metformin or St. John's wort (St John's wort can be stopped for the 28-day period of NPEP). 6. History or presence of allergy to DTG, FTC, TDF or their components 7. Alanine aminotransferase (ALT) ≥5 times the upper limit of the reference range or ALT ≥3 times and bilirubin ≥1.5 times the upper limit of the reference range 8. Unstable liver disease (as defined by the presence of ascites, encephalopathy, coagulopathy, hypoalbuminaemia, oesophageal or gastric varices, or persistent jaundice) or known biliary abnormalities (with the exception of Gilbert's syndrome or asymptomatic gallstones) 9. Severe hepatic impairment (Class C) as determined by Child-Pugh classification 10. Serum estimated Glomerular Filtration Rate (eGFR) \<60 mL/min/BSAc 11. Current therapy for hepatitis B infection 12. Serological evidence of chronic/active hepatitis B 13. Previous OPEP/NPEP containing DTG 14. A participant with a history or current evidence of any condition, therapy, or laboratory abnormality, or other circumstance that might confound the results of the study, or interfere with the participant's participation for the full duration of the study 15. Unable to complete study procedures