A temporary birth control option could soon be available to men.
Scientists from Osaka University and the University of Tsukuba, both in Japan, have just published findings that show promise for a shot or oral medication that would give men the same kind of temporary birth control currently afforded to women through methods like the pill.
The researchers took pieces of an immunosuppressant drug and injected it in mice. They found that the drug blocked a protein that is essential to making sperm. As a result, the mice found themselves child-free and loving it. Yet, the effect was short lived: a week later, the mice were back to being spermful. This gave researchers hope that they could develop a drug that men could take weekly or monthly, that would temporarily render them infertile, while leaving their long-term fertility in tact.
Since similar drugs have already gone through clinical trials and are available for other uses, it seems likely that the temporary male birth control could be on the market more quickly than it typically takes drugs to go from the research phase to pharmacy shelves.
Currently, male birth control is very limited. Vasectomies offer the most permanent option, and the FDA is still reviewing an injection called Vasalgel, which would render a man infertile for about ten years. This current research is the closest science has come to finding a male birth control that can be abandoned as soon as the man wants to become a father.
The researchers were originally testing the side effects of immunosuppressant drugs on fertility, when they discovered that these effects could actually be controlled, and used to one's advantage. An enzyme called calcineurin, which plays a role in the immune system, appears to be present in cells that produce sperm, so drugs which act on the immune system in this way can also have an effect on sperm production.
The mice who were rendered infertile were still able to mate and ejaculate normally, but were unable to impregnate their not-at-all-disappointed female partners. Although about 80% of promising mice studies do not ultimately result in findings that are applicable to humans, the researchers are hopeful that because the effect on human fertility was already reported, this particular finding could mean a temporary male contraceptive will be available soon.
