A study presented at the 11th International AIDS Society Conference on HIV Science suggests that pre-exposure prophylaxis (PrEP) pills work at full potency in women of trans experience who use feminizing hormones—in fact, the data showed that women taking feminizing hormones were more likely to take the HIV prevention pills.
Thirty-eight Brazilian trans women agreed to be divided into two groups: 14 took tenofovir disoproxil fumarate/emtricitabine (Truvada or a generic equivalent) without using feminizing hormones for 12 weeks; the other 24 women started PrEP while also taking a specified hormone regimen. Twelve weeks later, all the women could use the feminizing hormone regimen of their choice. The researchers checked their blood for any differences in levels of PrEP drugs depending on whether or not the women were concurrently taking hormone therapy.
The verdict was that there was a difference—but it wasn’t what many transgender people had feared. Instead of feminizing hormones blunting the potency of PrEP, women using hormone therapy plus PrEP in the first part of the study had higher PrEP drug levels. This wasn’t because feminizing hormones boosted the power of the pills but because the women taking hormones were more likely to follow through on taking PrEP.
At 12 weeks, 79% of women in the PrEP plus hormone therapy group had drug concentrations consistent with taking four or more pills a week, compared with 64% in the PrEP-only group. By the time the second measurements were taken at week 48, only 17 women were still on PrEP, but 93% of them had drug levels consistent with taking the pills at least four days a week.
“Oral PrEP is clinically effective among trans women with HIV risk on hormones,” said Vitória Berg Cattani, MSc, a pharmacist at Instituto de Pesquisa Clinica Evandro Chagas in Rio de Janeiro.