Testosterone Tested as Male Contraceptive
Study Shows Monthly Injections in Men Can Prevent Partners' Pregnancies
Studying Testosterone's Effects continued...
The reasons for this are not clear, but Gu tells WebMD that any hormonal birth control developed for non-Asian men is likely to include another hormone -- progestin.
Studies have shown the testosterone-progestin combination to be very effective in suppressing fertility in white men.
The Chinese men in Gu's study took monthly injections of 500 milligrams of TU in tea seed oil for 30 months. This formula is not available in the U.S. and is indicated to treat low testosterone levels with injections typically given every three months.
Over the course of the trial, nine pregnancies occurred in the partners of 1,045 study participants, or roughly one pregnancy for every 100 men.
There was no evidence of major side effects, and all but two of the men in the study returned to normal fertility after stopping the injections. The average time it took for the men to return to normal fertility was around six and a half months.
Gu says more study is needed to examine the long-term safety of the TU treatment.
In an editorial accompanying the study, male fertility researcher David Handelsman, MD, of the University of Sydney writes that several other promising male contraceptives are under development with little help from the pharmaceutical industry.
He argues that there is a clear need and demand for a practical hormonal contraceptive option for men.
"Whatever the reasons for the strike by large pharmaceutical companies ... the disconnect between the lay and medical perception of both a need and a niche for [hormonal male contraception], on the one hand, and the failure of the pharmaceutical market to deliver a product, despite the demonstration of feasibility, is puzzling, indeed," he writes.
Lissner says governments and nonprofit foundations are taking the lead in developing new hormonal and nonhormonal male birth control.
She points out that the Gates Foundation has made contraceptive development one of the four pillars of its new reproductive strategy.
"We are very fortunate to have a more promising political environment than we have had," she says. "This is a good time for male contraception, but I don't think we can count on the pharmaceutical companies to do this."