Press Release

Testosterone Therapy Fails to Treat Ejaculatory Dysfunction

Washington, DC July 09, 2015

Clinical trial first to evaluate potential treatment for common male sexual disorder

Men who have ejaculatory disorders and low testosterone levels did not experience improved sexual function after undergoing testosterone replacement therapy, according to a new study published in the Endocrine Society’s Journal of Clinical Endocrinology & Metabolism.

Estimates indicate between 10 percent and 18 percent of men have problems with inability to ejaculate, decreased volume of ejaculation, decreased force of ejaculation and delayed time to ejaculation. This is a separate neurobiological problem from erectile dysfunction, and there is no FDA-approved treatment for the condition.

“This is the first clinical trial examining the treatment of a very common but poorly understood condition that affects men’s physical health as well as their interpersonal relationships,” said one of the study’s authors, Darius A. Paduch, MD, PhD, of NewYork-Presbyterian Hospital/Weill Cornell Medical Center and Weill Cornell Medical College in New York, NY. “Although the participants in this study did not experience any significant improvement in ejaculatory function, we hope our work will spur the development of additional clinical trials to find treatments for this condition.”

As part of the multi-center, double-blind, randomized, placebo-controlled, 16-week trial, 76 men with ejaculatory dysfunction were assigned to receive either a 2 percent testosterone solution applied on the skin or a placebo. Sixty-six men completed the study. The men were all 26 years or older with total testosterone levels of less than 300 ng/dL found on two separate tests.

During the study, participants had their testosterone levels measured periodically to determine how well the hormone replacement therapy was working. To gauge ejaculatory function, researchers collected semen samples and had participants complete sexual health questionnaires and logs.

Although the men who received testosterone replacement therapy had higher scores on the Men’s Sexual Health Questionnaire on ejaculatory dysfunction than the men who took the placebo, the difference was too small to be statistically significant. The researchers also found no or little improvement in ejaculate volume or orgasmic function.

One possible explanation may be that testosterone therapy was not effective in all of the men who received it. Among the participants who used the topical testosterone solution on their skin, about 70 percent showed an increase in the levels of testosterone above 300 ng/dL in their blood, Paduch said. A subsequent analysis found that the men whose testosterone levels rose above 300 ng/dL did show a statistically significant improvement in ejaculatory function when compared to men whose testosterone levels did not reach this threshold.

“Our findings suggest physicians who are treating men with ejaculatory dysfunction need to look at other reasons for delayed ejaculation than hypogonadism,” said another of the study’s authors, Shehzad Basaria, MD, of Brigham and Women’s Hospital and Harvard Medical School in Boston, MA. “More research is needed to determine whether a longer course of testosterone therapy or other treatment options can benefit men with ejaculatory dysfunction.”

The Endocrine Society’s Clinical Practice Guidelines on testosterone therapy in adult men recommend prescribing testosterone only to men who have unequivocally low levels of the hormone and decreased libido, erectile dysfunction or other symptoms of hypogonadism, a condition that results from low testosterone.

Other authors of the study include Paula Polzer and Xiao Ni of Eli Lilly and Company’s Lilly Research Laboratories in Indianapolis, IN. Eli Lilly and Company sponsored the research.

The study, “Testosterone Replacement in Androgen-Deficient Men with Ejaculatory Dysfunction: A Randomized Controlled Trial,” was published online at, ahead of print.

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