Study: PrEP Significantly Less Effective on Women than Men

Are cis women less protected by use of PrEP than both transgender women and cis men? One might think that this progressive drug would react no different between these groups of people but new data suggests otherwise. Professor Bob Grant, investigator of the iPrEx and PrEP study in trans women and gay men states that, “PrEP did protect cisgender women from infection,” but in order to reach levels that offer this protection, they’d need to take it almost everyday without missing a dose. He cited 24 cases of women in PrEP studies  where drug levels were tested before and just after infection and many of the results concluded that women taking four to five pills a week had higher infection rate than men and trans women taking the same dose. With this information, we can assume that a higher and more consistent adherence might be necessary for full protection in cis women.

Pharm. D. Angela Kashuba of North Carolina examined the biological reasons for this and discovered that it takes longer for PrEP to reach vaginal tissue than rectal tissue. Some instances have even shown that drug levels may never reach protective levels in the vagina at all. PrEP stays in rectal tissue far longer and reaches the tissue much faster than in the vagina, it also takes a lower dosage to reach higher levels. The data seems pretty conclusive. As long as cis women take PrEP every day and begin their treatment a few weeks before possible HIV exposure, they should be fully protected. For those wanting to add extra precaution, it is suggested to use other protective barriers, such as, condoms.  

This data made me think though, what does that mean for pre op transgender men? Most studies are done using gay cis males and very few trans females that have sex with cis men. Even fewer studies have been done using cisgender women and hardly any information at all has been collected on trans men taking PrEP. With the growing number of trans male adult entertainers and even those that simply enjoy an adventurous sex life, isn’t it vital that a study be done? Can hormone replacement therapy (HRT) affect the potency of the drug? What about atrophy of vaginal tissue that so often occurs after the start of testosterone? There are so many questions left unanswered because the percentage of trans men that sleep with cis males is so low but that doesn’t mean this group of people is less important. PrEP is a breakthrough drug with huge potential but there are still so many questions that need to be addressed before we can say it is beneficial for everyone.