The marketing of a hormone-based contraceptive for men has moved a step closer following the discovery that men using it in clinical trials are recovering their fertility within months of coming off it. Eithne Donnellan, Health Correspondent, reports
This is a crucial breakthrough in the search for something akin to a contraceptive pill for men. Up until now it was not known if men who had taken the treatment could ever recover their fertility.
It has now emerged, however, from research conducted in Australia that men on the treatment can on average recover their fertility within three to four months of coming off the contraceptive. The research is published in The Lancet today.
Dr Peter Liu, who is based at the Anzac Research Institute at the University of Sydney, told The Irish Times last night that it was known for quite some time that hormonal contraceptives which had been in development for men were effective in preventing pregnancy but it was not known until now that the effects of these methods were reversible.
"This is an important step. Until now we did not know these were reversible. This is an important piece of the puzzle," he said. He said he did not know, however, how soon these contraceptives would be available worldwide. "I've no idea . . . but it will be at least a few more years," he said.
The formulation closest to being marketed was an injection, he said, but those behind it would first have to apply to have it licensed by the regulatory authorities.
Dr Liu explained that the new information was based on the analysis of "primary data" from 30 studies published over a 25-year period from 1990 to 2005 which had not been previously looked at. "The recovery times from them had not been reported before," he said.
Data was available for around 1,500 men and the studies in which they were involved differed in the doses of contraceptive used. The average time for sperm recovery to 20 million/ml, an indicator of fertility, was 3.4 months. "These findings thereby increase the promise of new contraceptive drugs allowing men to share more fairly the satisfaction and burden of family planning," Dr Liu said.