This study examined the drug levels of the antiretroviral agent tenofovir in rectal tissue after it has been used as a gel in the vagina and vice versa. (funded by NIH) Report Links: Justman J. et al, 2018. Pharmacokinetics and pharmacodynamics of tenofovir reduced-glycerin 1% gel in the rectal and vaginal compartments in women: A cross-compartmental study with directly observed dosing. J Acquir Immune Defic Syndr. Web Links: https://clinicaltrials.gov/ct2/show/NCT01768962 https://mtnstopshiv.org/sites/default/files/attachments/MTN-014%20Version%202%200%201May2013_FINAL~CLEAN.pdf