If women take a pill “the next morning” to prevent pregnancy, can men one day take a similar pill “an hour before” sex?
A new drug candidate renders male mice infertile within an hour and disappears in less than a day, the pilot study says, possibly pointing to a future method of on-demand male contraception.
The potential drug, which has not yet been tested in humans and is far from being available, joins a growing number of male contraceptives in development.
However, there are currently only two options available to men: condoms and vasectomy.
Previous drugs have suffered in part because of the belief that the reduction in side effects is much higher in men because they are not at risk of getting pregnant, and also because of a lack of interest from the pharmaceutical industry.
“For women, the entire burden of contraception now falls on our shoulders,” said Melanie Balbach, a pharmacology researcher at Weill Cornell Medicine in the US.
“We need new opportunities,” said Balbach, lead author of the study, published in Nature Communications.
The research team targeted an enzyme called soluble adenylilliase, which acts as a “switch” for sperm, said study co-author Yushin Pak, also of Weill Cornell Medicine.
He said that if the enzyme is disabled, the sperm will not be able to move.
In several different tests, the researchers showed that the enzyme-blocking compound renders mouse sperm immobile for 30 minutes to an hour.
The study found that the compound was 100% effective in preventing pregnancy within the first two hours and dropped to 91% within the first three hours.
After 24 hours, the mouse spermatozoa moved normally again.
Researchers are hoping to get one non-hormonal pill that works in less than an hour and lasts 6 to 12 hours, Buck says.
This will be very different from other options under development, such as the hormone gels that are currently being tested in humans, all of which take weeks or months to start working and stop working.
No side effects were observed in mice.
Previous studies have shown that infertile men who permanently stop producing soluble adenylate cyclase have an increased incidence of kidney stones.
Buck said this was a result of their enzyme always being low, which would not be the case for men taking the pill on demand.
Buck said the researchers hope to have the first human trials within three years, with the final product likely to take eight years.
Susan Walker, a contraception expert at Anglia Ruskin University in the UK who was not involved in the study, said she was “a little skeptical” that the pill would actually be commercialized because so many other attempts had failed.
But the “significant benefit” of the near-instant effectiveness is “the ability to see your partner take the pill,” she says.
Source: Science Alert
