Testosterone and Its Effects on Sexual Function

1. A long-term prospective study of the physiologic and behavioral effects of hormone replacement in untreated hypogonadal men — A.S. Burris et al. Journal of Andrology 1992; 13(4):297-304.

   Men with low levels of testosterone who had not yet been treated with supplemental hormone showed significantly higher levels of depression, anger, fatigue and confusion than did men with acceptable testosterone levels. During testosterone replacement therapy, scores improved. Also during treatment, these men reported increased sexual interest and greater numbers of spontaneous erections. (Design of Study: Hypogonadal men before and during testosterone treatment compared to untreated normal men and untreated infertile men; no placebo treated controls.)

2. Effects of androgen on sexual behavior in hypogonadal men — J.M. Davidson et al. Journal of Clinical Endocrinology and Metabolism 1979; 48(6):955-958.

   The study found that the effect of testosterone replacement on sexual activity in hypogonadal men is rapid, reliable, and not due to placebo effect. To maintain testosterone levels and adequate sexual function, testosterone replacement should be administered on an ongoing basis. (Design of Study: Hypogonadal men during double blind, randomized, cross-over treatment with sub-replacement and replacement doses of testosterone; no placebo treated controls.)

3. Improvement of sexual function in testosterone deficient men treated for one year with a permeation enhanced testosterone transdermal system — S. Arver et al. Journal of Urology, 1996; 155(5): 1604-1608.

   This study observed that nocturnal erections occurred more frequently with longer duration and greater rigidity, and patient assessments of sexual desire and weekly number of erections were higher in hypogonadal men when testosterone levels were normalized, as compared with measurements occurring during testosterone withdrawal. (Design of Study: Hypogonadal men during open-label testosterone treatment; not a controlled study.)

4. Androgen Replacement: Sexual Behavior, Affect and Cognition — A.W. Meikle, editor. Hormone Replacement, Contemporary Endocrinology. Humana Press, Totowa, NJ (in press).

   This chapter reviews studies that evaluate the effects of testosterone replacement on erectile function in hypogonadal males. (A review article; not a controlled study.)

Testosterone and Its Effects on Mood and Thinking

1. A long-term prospective study of the physiologic and behavioral effects of hormone replacement in untreated hypogonadal men — A.S. Burris et al. Journal of Andrology 1992; 13(4):297-304.

   Men with low levels of testosterone who had not yet been treated with supplemental hormone showed significantly higher levels of depression, anger, fatigue, and confusion than did men with acceptable testosterone levels. During testosterone replacement therapy, scores for the previously untreated hypogonadal men improved indicative of less depression, anger, fatigue, and confusion. (Design of Study: Hypogonadal men before and during testosterone treatment compared to untreated normal men and untreated infertile men; no placebo treated controls.)

2. Androgen-behavior correlations in hypogonadal men and eugonadal men. II. Cognitive abilities — G.M. Alexander et al. Hormones and Behavior 1998; 33(2):85-94.

   Reasoning abilities were assessed in 33 men with low levels of testosterone who were receiving supplemental testosterone, 10 men with normal levels of testosterone who were given the hormone as part of a male contraceptive clinical trial, and 19 men with normal testosterone levels who did not receive supplemental testosterone. Prior to and after being given testosterone the men completed tests that measured visual-spatial ability, verbal fluency, perceptual speed, and verbal memory. Men with low testosterone seemed to have lower levels of verbal fluency; these improved following treatment with testosterone. These data suggest that testosterone may play some role in influencing some aspects of reasoning and thinking. (Design of Study: Hypogonadal men before and during testosterone replacement treatment compared to normal men before and during high dose testosterone and untreated normal men; no placebo-treated controls.)

3. Testosterone replacement therapy improves mood in hypogonadal men — a clinical research center study - C. Wang et al. Journal of Clinical Endocrinology and Metabolism 1996; 81(10):3578-3583.

   The study evaluated changes in mood for 60 days in 51 hypogonadal men. Researchers found that testosterone replacement therapy in hypogonadal men improved their positive mood parameters including energy, well/good feelings, and friendliness. Testosterone replacement also decreased negative mood parameters including anger, nervousness, and irritability. (Design of Study: Hypogonadal men before and during testosterone treatment with a variety of testosterone formulations; not a controlled study.)