Newswise — WASHINGTON (April 12, 2016) — A review article published today in The Lancet Diabetes & Endocrinology journal discusses testosterone therapy for transgender men (female to male), outlining desired and undesired effects, potential risks, and additional benefits. The review also revealed a lack of research in this field, calling for more data.

“My review looks at published literature on testosterone therapy in transgender men — principally from the last 15 years,” said Michael S. Irwig, M.D., associate professor of medicine at the George Washington University (GW) School of Medicine and Health Sciences and director of the Andrology Center at the GW Medical Faculty Associates, who authored the article. “Overall, testosterone therapy appears to be quite safe in the short term.”

Testosterone therapy is prescribed for transgender men in order to obtain male secondary sexual characteristics, to improve well-being, and to decrease gender dysphoria. Within several months of starting testosterone therapy, transgender men begin to notice many desired effects such as increased facial and body hair, increased lean mass and strength, decreased fat mass, a deeper voice, increased sexual desire, cessation of menses, clitoral enlargement, and lower rates of gender dysphoria, perceived stress, anxiety, and depression, according to the review. The review also found that an additional benefit of testosterone therapy (with or without mastectomy) is a reduction in the risk of breast cancer.

However, potential undesired effects and risks were found to include acne, alopecia, lower HDL cholesterol, higher triglycerides, and a possible increase in systolic blood pressure.

The review looked at articles published in English and Spanish from January 2000 to May 2015 about testosterone therapy in transgender men and other populations for comparisons. A select number of older publications were also included. In the article, Irwig discusses a major limitation in the field being a lack of high-quality data. He cites that difficulties in obtaining this data stem from a lack of randomized controlled trials due to ethical issues, suboptimal control groups, loss to follow-up, difficulties in recruiting representative samples, few prospective studies, and few long-term studies. Because of this, long-term consequences of the therapy are somewhat unknown.

“Given that transgender medicine is a relatively new field, research is desperately needed, especially larger and longer studies looking at diverse populations,” said Irwig. “Only with this research can we be sure we are providing the best care possible to our transgender patients.”

“Testosterone Therapy in Transgender Men,” published in The Lancet Diabetes & Endocrinology journal on April 12, is available at

Media: To interview Dr. Irwig, please contact Lisa Anderson at [email protected] or 202-994-3121.


About the School of Medicine and Health Sciences:Founded in 1824, the GW School of Medicine and Health Sciences (SMHS) was the first medical school in the nation’s capital and is the 11th oldest in the country. Working together in our nation’s capital, with integrity and resolve, the GW SMHS is committed to improving the health and well-being of our local, national and global communities.