THE array of women’s birth control developed in the last 50 years reads like a trip through Willy Wonka’s factory. Patches or pills; rings and coils; injected, implanted or inserted, women have more options than ever before to protect themselves from unwanted pregnancy. Which makes the lack of progress on male contraception all the more striking. Men today rely on the same two methods they had in the 1950s, vasectomy and condoms. But vasectomies are drastic, and lads often claim that condoms are fiddly and spoil the mood. The burden of birth control, then, rests squarely on women.
That may at last be about to change. A new drug, called JQ1, has proven to be a foolproof male contraceptive—though the males in question are for now murine, not human. JQ1 began life as an anticancer treatment, but it caught the attention of Martin Matzuk at Baylor College of Medicine in Houston, Texas. Dr Matzuk noticed that the gene it targets is similar to another, called BRDT, which is only active in the testes. By turning other genes on and off, BRDT governs the production of healthy sperm. Mice with their BRDT gene removed are sterile, and a study from 2010 found that European men with mutations in BRDT are more likely to have reduced sperm counts.
When it binds to BRDT, JQ1 accomplishes a similar effect temporarily. As Dr Matzuk and colleagues report in Cell, male mice given a relatively mild doses of JQ1 for six weeks showed an 89% drop in their sperm count, and the sperm they did produce were terrible swimmers. In the final month of testing, those which received a high-enough dose of the drug did not beget offspring, despite the fact that each was provided two receptive females and all displayed normal male desires, while mice not on the drug were fathering two litters a month.
Crucially, these effects were fully reversible. Once taken off the drug, the males reverted to normal sperm counts, sufffered no permanent damage to their reproductive organs, and sired typical numbers of healthy offspring. Mice on higher doses of the drug, or treated for longer, were slower to recover, but they, too, regained their prowess within one to three months.
That is welcome news for drug development. At the moment, research into male contraceptives has focused on testosterone-based drugs. They have drawbacks: higher levels of testosterone might increase the risk of prostate cancer or have knock-on behavioural effects (anabolic steroids, which mimic testosterone in the body, have been linked to “roid rage”). Worse, testosterone’s contraceptive effects are not uniform across populations. It appears to work better among Chinese men, for instance, than Caucasians.
The next step for Dr Matzuk and his team will be to tweak the structure of the drug so that it dovetails even more snugly with BRDT. This ought to minimise the odds of its own undesirable side effects. If all goes to plan, Dr Matzuk thinks, a human version the drug might be available to men within a decade. Womenfolk can’t wait to see him proved right.
Curtailing Masturbation 