Researchers in the US reported an effective and reversible solution to male contraception from studies with mice. 

Most existing male contraceptive options are limited to condoms or vasectomy, the latter being sometimes challenging to reverse. Many experimental approaches have so far focused on hormonal treatments, which can cause many unwanted side effects.  

Scientists at Cornell University, New York, were motivated to look for other solutions, and Paula Cohen, lead author of the study, published at PNAS, stated: “We were really motivated to look for nonhormonal contraceptive targets in the testis, something that stops sperm production without affecting male libido and secondary sex characteristics.” 

To this end, the team used a small molecule, JQ1, previously used in cancer research, to disrupt cell division at an early step in sperm production. 

In male mice treated with JQ1 for three weeks, sperm production was stopped temporarily while preserving the stem cells that allow fertility to recover later. When treatment stopped, sperm production resumed, and after using these mice for breeding, they found their offspring were healthy and fertile as well. 

The team is now working on more targets to temporarily halt sperm production even more effectively and offer a potential future contraceptive development, which could be either a patch or an injection given every three months.