From
ABC news:
A large study published Monday in the Journal of Clinical Endocrinology and Metabolism indicates that science may be bringing us closer to a male "pill," although the idea of hormones for male birth control still stokes a heated debate among doctors.
Researchers recruited more than 1,000 Chinese men who had fathered at least one child two years before the study with their partners to receive injections of testosterone undecanoate (TU) in tea seed oil every month.
After two years, the injections had 95 percent effectiveness for preventing pregnancy overall, and about 98 percent effectiveness for men whose sperm levels dropped off at expected levels within the first few months of the trial.
Male contraceptive researcher Dr. John K. Amory was impressed by the ability of the injections to drop sperm counts.
"The goal is to try to get to 99 percent effectiveness [for pregnancy prevention]," said Amory, who is an associate professor of medicine at the University of Washington in Seattle
Although
testosterone usually triggers sperm production, Amory said too much testosterone can shut down the testes.
The authors write that more long-term studies of testosterone injections are needed for safety, but "that these promising findings provide encouragement that male hormonal-contraceptive regimens may offer a novel and workable alternative to existing family planning options."
But not everyone agrees that hormones for male birth control are novel, or a workable alternative.
It's really not new and it's been abandoned for a number of reasons," said Dr. Larry Ross, past president of the American Urological Association.
The first reason, Ross said, is that testosterone injections proved to be unreliable in the past.
"Failure rates as high as 20 percent have been reported," said Ross, who is also professor of urology at the University of Illinois at Chicago.
On the other hand, Ross said testosterone injections can be too effective and, over time, can sterilize a man.
But researchers of male birth control in the United States say they have to kindly disagree with the notion that the effects of abuse rule out any future for testosterone as birth control.
"I'm not sure I agree that it can lead to sterility," said Armory, who added that in the 35 male hormonal-contraception studies using testosterone he has seen, there has never been a case of irreversible sterility.
Dr. Ronald Swerdloff, a veteran male contraceptive researcher, believes there are issues other than safety or effectiveness that are keeping male hormone contraception research from reaching its goal.
"This as been known for 15 and 20 years that [testosterone injections] are quite effective and that there is a limitation that it didn't work on everybody," Swerdloff said. "But there's another problem and the other problem is that it doesn't work right away," he said.
Unlike the condom, which works immediately, or the pill which works within one month's cycle, a man on testosterone may have to wait three months before sperm production shuts down.
Swerdloff thinks the lack of interest by pharmaceutical companies may be another contributor to barriers for male hormone contraception research.
Swerdloff believes that -- unlike a new cancer drug that people need and would pay big money for -- pharmaceutical companies don't see the profits in male contraception investments when healthy people already have relatively cheap, safe options for women's birth control or other methods.
"There would be a considerable up-front cost," Swerdloff said.
But at least all doctors can agree that one thing male contraception research isn't missing is interest by the public.