An article published in the August 2016 issue of the Journal of Clinical Endocrinology & Metabolism reports increased sexual interest and activity among men over the age of 65 years receiving testosterone replacement therapy.

Testosterone is a hormone that declines with age in humans. An increasing number of men are opting to receive testosterone replacement when indicated by blood test results. The current investigation, which is part of the Testosterone Trials series, is the largest of its kind to date among men in this age group.

Four hundred-seventy men aged 65 and older with low libido and testosterone levels of less than 275 nanograms per deciliter (ng/dL) were enrolled in a double-blind trial. Participants were assigned to receive testosterone gel or a placebo for one year. Three questionnaires administered quarterly assessed sexual interest and function.

Men who received testosterone experienced improvements in ten out of twelve measures of sexual activity, while those who received a placebo reported no significant changes. Increases in serum total and free testosterone were associated with improved desire and sexual activity.

"For symptomatic older men with low testosterone levels, testosterone therapy led to consistent improvement in most types of sexual activity," concluded first author, Glenn R. Cunningham, MD, of Baylor College of Medicine and Baylor St. Luke's Medical Center in Houston.

"Our findings indicate low testosterone is one cause contributing to reduced libido and erectile dysfunction in older men," he added. "Men experiencing these symptoms should be evaluated for testosterone deficiency."