Safety of Physiological Testosterone Therapy in Women: Lessons from Female-to-Male Transsexuals (FMT) Treated with Pharmacological Testosterone Therapy

Introduction. The safety of long-term physiological doses of testosterone (T) therapy in women with sexual dysfunction is a contentious issue, in part, because of fear of adverse effects, such as breast cancer, vascular disease, and excessive virilization. This unsubstantiated fear has hampered progress in treating women with sexual dysfunction using T therapy in physiological doses to achieve circulating levels in the normal range. Aim. To examine evidence derived from studies in female-to-male transsexuals (FMT) treated with supraphysiological (pharmacological) doses of T for long periods of time with no apparent major adverse effects. Methods. A comprehensive literature search of relevant articles published between 1980 and 2010 pertaining to the topic of T in FMTs was performed using PubMed. The following key words were used: female-to-male transsexuals; testosterone; virilization; gender re-assignment; and androgen therapy in women. Relevant articles were retrieved, reviewed, and the information was analyzed and evaluated for study methodology and major findings. Main Outcome Measures. Data from peer-reviewed publications were critically analyzed and the information was summarized. Results. The data from the studies reported in the literature to date strongly suggest that treatment of FMTs with supra-physiological doses of T had minimal adverse effects. No increase in mortality, breast cancer, vascular disease, or other major health problems were reported. Conclusions. No significant serious adverse effects were reported in FMTs treated with pharmacological doses of T. In light of the findings with supraphysiological doses of T, we suggest that treatment with T at doses producing physiological levels in women with sexual dysfunction are expected to produce limited and minimal adverse effects. Traish AM, and Gooren LJ. Safety of physiological testosterone therapy in women: Lessons from female-to-male transsexuals (FMT) treated with pharmacological testosterone therapy. J Sex Med 2010;7:3758-3764.