‘Stopping sperm from going its way’: US researchers report promising progress in search for ‘male pill’

Jochen Buck, PhD, and Lonny Levin, PhD, professors of pharmacology at Weill Cornell Medical College, said the discovery could be a “game changer” for contraception. In their abstract of the study (“On-demand male contraception via acute inhibition of soluble adenylate cyclase”) published in Nature Communications on 14 February, they write: “Nearly half of pregnancies are unintended; Therefore, existing family planning options are insufficient.”

What did the research say?

Basically, this study is to show a proof-of-concept, and whether the idea of ​​this pill is feasible. The purpose here is to work on slowing the mobility or movement of sperm or male gametes, which fertilize female gametes or eggs during human reproduction.

According to the Weill Cornell Medicine Newsroom, the study benefited from the study of a single protein. “Dr. Levine challenged Dr. Barker to isolate an important cell signaling protein called soluble adenylyl cyclase (sAC), which has long baffled biochemists,” it said. Later, the two began working together as part of a team.

They found that mice genetically modified to lack sAC were infertile. In 2018, Dr. Melanie Balbach, a postdoctoral researcher in their lab, discovered that giving mice a drug that inactivates the sAC resulted in sperm unable to propel themselves forward. Therefore, sAC inhibition was viewed as a potentially safe contraceptive option, as another team reported that men lacking the gene encoding sAC were infertile but otherwise healthy.

How was the study conducted?

found that a single dose of a sAC inhibitor called TDI-11861 immobilized mouse sperm for up to two and a half hours, and that this effect persisted in the female reproductive tract after copulation. After three hours, some sperm began to mobilize; by 24 hours, almost all sperm had resumed normal motility.

“Our inhibitor works within 30 minutes to an hour,” Dr. Barbach said. “All other experimental hormonal or non-hormonal male contraceptives take weeks to reduce sperm counts or render them unable to fertilize eggs.”

The team now plans to conduct these experiments in different preclinical models, eventually hoping to lead to clinical trials in humans.

Why has the male contraceptive pill been so difficult to develop?

In general, contraception has been focused on women. In 1960, oral contraceptives were approved for marketing. While the pill isn’t entirely without controversy, often leading to side effects like blood clot risk and even cancer risk, according to some studies, it also has big benefits. It allows women to have more agency in reproduction.

The pill works by regulating the hormones progesterone and estrogen, preventing sperm from fertilizing the egg.U.S. birth control pill researcher Christina Wang told Washington post Biology may be at play, explaining why the same thing doesn’t happen to men. Women produce one egg per month, while men produce far more sperm. Therefore, it is more challenging to develop a method.

Sometimes, after a 2016 study found even mild side effects, such as acne or mood swings, studies were dropped, even though women had been dealing with them for years. But it’s also about changing the standard of what is accepted in such trials now, compared to when the contraceptive pill for women was being developed in Western countries in the mid-20th century.