Effect of testosterone formulations on hematocrit in transgender individuals: A systematic review.

All testosterone formulations result in an increase in Hct, irrespective of dose, formulation, and administration method. Smoking, higher age at initiation of the testosterone therapy, higher BMI, and a predisposing medical history are associated with this increase in Hct. The difference in effect of TE and TU on Hct is conflicting, although it is important to point out that these data come from observational studies, retrospective, and with a small-sample size.