Transgender women taking PrEP have lower levels of PrEP drugs than cisgender men

aidsmap/nam, November 9th 2018

A study presented at October’s HIV Research for Prevention conference (HIVR4P) in Madrid shows that transgender women who are taking feminising hormones and also taking pre-exposure prophylaxis (PrEP) have levels of the PrEP drugs tenofovir and emtricitabine in their blood that are about 25% lower than those in cisgender men, and levels in rectal tissue cells about 40% lower. Tenofovir levels in rectal tissue were 44% lower.

However, the study also confirmed that the interaction between hormones and PrEP did not appear to go the other way; blood levels of estradiol, the one hormone all of the transgender women took in one form or another, do not appear to be affected by PrEP.