The drug is formulated as a gel since testosterone is cleared too quickly from the body when it’s taken as a pill. The progestin in the gel, called Nestorone, blocks the natural production of testosterone in the testes, where sperm is made. The testosterone replaces the hormone in the blood.
“You are cutting it off at the source, but replacing it everywhere else at a levels that keeps everything else functioning normally,” Blithe said, pointing out that testosterone levels in the testes are 50 times higher than the amount normally found in the blood.
The researchers will track men for four to 12 weeks to ensure their sperm production has fallen significantly enough to prevent conception, with women using an alternative form of birth control just in case. After that, couples will rely on the gel alone. If the results are positive, another larger trial will be needed before the product could get approval.
This story was provided by Bloomberg News.