Transgender men taking testosterone had significantly higher Ferriman-Gallwey scores (median 5 [IQR 3-9], P < .001) than cisgender women and transgender men not on testosterone; however, their scores remained lower than those of cisgender men (median 10.5 [IQR 7.25-12], P < .001) (Fig 2).
Moreover, having taken testosterone for a longer duration correlated with greater body hair growth, and the authors found that testosterone “showed the greatest effect on hair growth on the lower abdomen”:
Notably, in this sample, 52% of trans men on testosterone experienced chest acne compared to only 6.7% of cis men. Park, Carter, & Larson (2019) explored this phenomenon further, looking into particular factors associated with the presence of acne in a sample of 55 trans men who had taken testosterone for at least two years and had no history of acne prior to treatment. These patients had a median testosterone level of 630 ng/dL, and the authors found that levels higher than this were significantly associated with the development of acne. Additionally, smoking and a higher body mass index were linked to a greater likelihood of acne. The likelihood of having experienced acne increased substantially during the first two years of taking testosterone:
The authors further note that management of undesired acne may be possible through alteration of testosterone dosage:
Nakamura et al reported that during the first 6 months only, the most commonly desired virilization effects were dose dependent. If a transgender man begins to develop acne, it may be possible to personalize his testosterone therapy depending on transition goals, priorities, risk factors, and other comorbidities.