Biology and sexual orientation INAH3 weight for the heterosexual male brains was significantly larger than for the heterosexual female brains, while the results for the gay male group were between those of the other two groups but not quite significantly different from either. The neuron count also found a male-female difference in INAH3, but found no trend related to sexual orientation. A 2010 study, Garcia-Falgueras and Swaab asserted that "the fetal brain develops during the intrauterine period in the male direction through a direct action of testosterone on the developing nerve cells, or in the female direction through the absence of this hormone surge.
Transgender hormone therapy (male-to-female) to a higher boost in plasma estradiol levels; however, the long-term side effects haven’t been studied and the safety of this route is unclear. As with any pharmacological or hormone therapy, there are potential side effects, which in the case of transgender hormone therapy include changes in sexual functioning. These have the ability to significantly impact sexual functioning, either directly or indirectly through the various side effects, such as cerebrovascular disorders, obesity, and mood fluctuations. In addition, some research has found an onset of diabetes following feminizing hormone therapy, which impairs sexual response. Whatever route an individual and their doctor