Scalp Hair Parameter Changes in Transgender Individuals Commencing Gender-Affirming Hormone Therapy: A 24-Week Prospective Observational Study

February 2025 in “ Journal of the American Academy of Dermatology ”

Gia Toan Tang, Rodney Sinclair, Shalem Leemaqz, Ada S. Cheung

gender-affirming hormone therapy masculinizing hormone therapy testosterone androgenetic alopecia feminizing hormone therapy estradiol antiandrogens hirsutism sex steroids androgens anagen phase telogen phase estrogens catagen phase AGA

TLDR Feminizing hormone therapy increases hair counts and improves hair-related quality of life, while masculinizing therapy may reduce large terminal hairs.

This study investigated the effects of gender-affirming hormone therapy on scalp hair parameters and quality of life in transgender individuals over 24 weeks, involving 15 participants on masculinizing hormone therapy (MHT) and 19 on feminizing hormone therapy (FHT). MHT was associated with a decrease in large terminal hairs but did not significantly alter total hair counts or hair-related quality of life, potentially accelerating pre-existing androgenetic alopecia. Conversely, FHT significantly increased hair counts and improved hair-related quality of life. The study highlights the need for longer-term research with larger sample sizes due to its limitations.