Male Libido Gone MIA? There May Be A Fix For That

As men age, testosterone levels naturally decrease. But as our longevity increases -- and with sex being such an important part of our lives -- the issue of men's diminished interest and ability in having sexual relations was bound to be addressed.

Testosterone replacement therapy has long been used in individuals with testosterone deficiency, whether due to disease or aging. But the therapy's effectiveness at addressing sexual dysfunction in older men has not been investigated in great depth before this study, notes its authors.

Hypogonadism -- a reduction or absence of hormones secreted by the testes -- is thought to affect 40 percent of men over the age of 45, although the study estimates that 95 percent of them go without diagnosis or treatment.

Testosterone replacement therapy for hypogonadal men has been found to improve sexual function, mood, libido, bone density, muscle bulk, and muscle strength, reports the study. It also may decrease visceral and peripheral body fat and can reduce insulin resistance and blood sugar.

Previous research has shown that testosterone treatment helps improve sexual function in younger men who have lower androgen levels due to problems with the testes, hypothalamus, or pituitary. This is the largest testosterone therapy study to date that includes how testosterone treatment might help sexual dysfunction in older men.

The research is part of the so-called Testosterone Trials, a series of seven studies looking into hormone therapy in men over 65 years of age. This particular study, conducted through Baylor College of Medicine and Baylor St. Luke's Medical Center in Houston, reviewed data from 470 men. All of the subjects were at least 65, reported having a low libido, and had a partner willing to have intercourse at least twice a month. The men either received testosterone gel -- the most common form of testosterone therapy -- or a placebo. The results showed that of the 12 sexuality measurements in the questionnaire, 10 were significantly improved for men in the testosterone group. These measures included frequency of intercourse, nighttime erections, and masturbation.

The only two measures that did not show any change were "flirting by others" and "day spontaneous erections."

In comparison, the men in the placebo group showed no change.

As the authors concluded: "Our findings indicate low testosterone is one cause contributing to reduced libido and erectile dysfunction in older men. Men experiencing these symptoms should be evaluated for testosterone deficiency."