whatweknow.inequality.cornell.edu/topics/lgbt-equality/%20what-does-the-scholarly-research-say-about-the-well-being-of-transgender-people%20/
Some excerpts:
"We conducted a systematic literature review of all peer-reviewed articles published in English between 1991 and June 2017 that assess the effect of gender transition on transgender well-being."
"This search found a robust international consensus in the peer-reviewed literature that gender transition, including medical treatments such as hormone therapy and surgeries, improves the overall well-being of transgender individuals. The literature also indicates that greater availability of medical and social support for gender transition contributes to better quality of life for those who identify as transgender."
"Regrets following gender transition are extremely rare and have become even rarer as both surgical techniques and social support have improved. Pooling data from numerous studies demonstrates a regret rate ranging from .3 percent to 3.8 percent. Regrets are most likely to result from a lack of social support after transition or poor surgical outcomes using older techniques."
"the health and well-being of transgender people can be harmed by stigmatizing and discriminatory treatment."