Male contraceptive pill a step closer following studies on mice

Researchers in the US have tested a contraceptive pill on mice and found it rendered them infertile through producing fewer, less mobile sperm.

The drug, the JQ1 compound, was initially discovered by scientists searching for cancer cures. It has been found to be effective in tests for lung cancer and leukaemia, and circulated to over 350 laboratories.

Dr James Bradner, of the Dana-Farber Cancer Institute (Boston, US), published a paper about JQ1 in the journal, Cell. He said: “Our findings demonstrate that, when given to rodents, this compound produces a rapid and reversible decrease in sperm count and mobility with profound effects on fertility. These findings suggest that a reversible, oral male contraceptive may be possible.”

Of the 14 options presented in the NHS leaflet, “Your Guide to Contraception”, only two are for men: condoms and vasectomies.

While the contraceptive pill for women has been around for over 50 years, development in alternative male contraception has been slow and faces a number of challenges: funding, safety standards, concerns about uptake and the prolific nature of sperm. While women produce one egg a month, sperm are generated at a rate of 1,000 a second.

Newer methods are focusing on non-hormonal contraception and addressing the motility of sperm and their ability to penetrate eggs.

Researchers observed that when JQ1 was administered, the testes of the mice shrank due to the diminished number of sperm. They said the mice were temporarily infertile, but that their testosterone levels and sex drive remained unaffected. With the cessation of the drug, sperm production returned to normal.

A marketable drug is most likely to be a long way off. Dr Bradner said:  “While we will be conducting more research to see if we can build on our current findings, JQ1 shows initial promise as a lead compound for male contraception.”

Jane Evans