Approximately 5 to 8 million males in the United States have a deficiency of the sex hormone testosterone, reports the UCLA Health System Department of Urology. Low testosterone levels, or male hypogonadism, can occur with certain inherited diseases and a variety of medical conditions that develop during life. For many males with hypogonadism, correction of the hormone deficiency with testosterone replacement therapy proves beneficial. Hormone-related side effects, however, may develop.
Acne
Male testosterone replacement therapy may cause new or worsening acne. Testosterone stimulates the production of oil, or sebum, from the sebaceous glands of the skin, explains the New Zealand Dermatological Society on the patient information website DermNet NZ. Increased sebum production can lead to mild to moderate acne.
Elevated Red Blood Cell Count
Testosterone stimulates bone marrow production of red blood cells. Overproduction leading to an abnormally elevated red blood cell level, or polycythemia, proves a common side effect of male testosterone replacement therapy. In a 2008 article published in "The Journal of Clinical Endocrinology & Metabolism," Dr. Andrea Coviello of Boston University School of Medicine and colleagues report that polycythemia proves the most frequent side effect of male testosterone replacement therapy. The authors further note that this side effect proves more common among older men, age 60 to 75, compared to younger men, age 18 to 35. Increased thickness of the blood associated with polycythemia can lead to complications, including worsening heart failure and the development of blood clots.
Breast Enlargement
Males on testosterone replacement therapy may experience breast enlargement, reports the Cleveland Clinic. This side effect occurs when the body tissues convert supplemental testosterone to the female hormone estrogen, which stimulates breast tissue growth. Breast enlargement associated with male testosterone replacement therapy may prove permanent.
Decreased Sperm Production
Hormone replacement therapy among males with a testosterone deficiency typically causes reduced sperm production, potentially leading to temporary infertility. Supplemental testosterone diminishes the release of pituitary hormones called gonadotropins. The reduced gonadotropin level causes slowing or cessation of sperm production, explains Dr. David Handelsman on the endocrinology reference website Endotext.org. This side effect generally proves reversible with discontinuation of treatment.
Prostate Growth
Male testosterone replacement therapy may contribute to noncancerous growth of the prostate gland. Prostate tissue growth depends on the presence of testosterone. Among men with a testosterone deficiency, the prostate gland commonly shrinks. Hormone replacement therapy in testosterone-deficient men typically causes prostate regrowth in the first few months after beginning treatment. This regrowth is unlikely to cause obstructive urinary tract side effects, such as difficulty initiating urination or incomplete bladder emptying, reports Johns Hopkins Medicine.
The effects of male testosterone replacement therapy among men with preexisting prostate enlargement remains uncertain, report Dr. Eberhard Nieschlag and colleagues in a 2004 article published in journal "Human Reproduction Update." The long-term effects of testosterone replacement therapy on the prostate gland remains an area of active biomedical research.
References
- UCLA Health System Department of Urology: Testosterone Deficiency
- DermNet NZ: Sebum
- "The Journal of Clinical Endocrinology & Metabolism"; Effects of Graded Doses of Testosterone on Erythropoiesis in Healthy Young and Older Men; Andrea D. Coviello, M.D., et al.; 2008
- Cleveland Clinic: Testosterone Replacement Therapy
- Endotext.org: Androgen Physiology, Pharmacology and Abuse
