Feminizing hormones reduce sexual function in males.
Feminizing hormonal treatments lead to a lessening drive, erectile dysfunction, and shrinking of testes and penis , significantly compromising sexual function.
A Belgian doctoral thesis study  found that 69.7% of transwomen reported a decrease in sexual desire — while the opposite effect is found in transmen.
 Levine, S. (2018). Informed Consent for Transgendered Patients. Journal Of Sex & Marital Therapy, 45(3), 218-229. [Link]
 Elaut, E. (2014). Biopsychosocial factors in the sexual desire of contraception‐using couples and trans persons. Doctoral thesis, University of Ghent. [Link]