A few months back, I posted an article about some promising new developments in birth control for men. These included the “testicular zap,” which involves performing a specialized ultrasound on the testicles, as well as RISUG (Reversible Inhibition of Sperm Under Guidance), which involves injecting a chemical compound into the vas deferens that impairs the “swimming” capability of sperm that pass through it. Despite the potential of these methods, the last thing most guys want to hear in any discussion about birth control is that their scrotums need to be zapped or sliced open, so a lot of my male readers probably weren’t too impressed with these scientific discoveries. However, you guys (and many of your lady friends as well) will be pleased to hear that scientists may have finally discovered a reversible male contraceptive that won’t require bringing sharp objects or sound waves anywhere near your genitals.
In a brand new study, scientists explored the effects of a compound called JQ1 (which is actually an experimental cancer drug) in male mice . All of the mice were given a daily injection in the abdomen, with half of the mice receiving JQ1 and the other half receiving a placebo solution. Mice that received JQ1 not only came to have significantly lower sperm counts than those given the placebo, but the sperm that was produced was of much lower quality. Importantly, this effect occurred without changing testosterone levels or sexual behavior (i.e., the JQ1-treated mice continued to engage in typical male mating behavior).
The way JQ1 works is by binding to a specific protein inside the testes that is essential for normal sperm production. By effectively “taking out” this protein, the testes’ ability to make viable sperm decreases substantially.
So what happened when the injections stopped? All of the male mice treated with JQ1 saw their sperm count and quality rebound to normal levels and each of these mice sired offspring within 6 months of their last injection. Thus, the effects of the compound appeared to be completely reversible. I should note that some of the mice recovered fertility faster than others, but that depended upon the amount of the compound they had been given. Specifically, infertility lasted longer when the contraceptive doses were larger.
The only apparent side effect of JQ1 was that it reduced the size of the testes while the males were receiving the injections. However, once the injections stopped, testicle size increased back to where it was before.
These findings are the first promising lead we have in the search for a male equivalent of “the pill.” The advantages of this particular method (aside from the fact that the genitals go untouched) are that it is hormone-free, appears to be reversible, and doesn’t seem to put a damper on male libido. Of course, much more testing is obviously needed, and clinical trials in humans are years away (if they ever happen at all), but the results of this research give us reason to believe that there may one day be a contraceptive pill for men.
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 Matzuk, M. M., McKeown, M. R., Filippakopoulos, P., Li, Q., Ma, L., Agno, J. E., … Bradner, J. E. (2012). Small-molecule inhibition of BRDT for male contraception. Cell, 150, 673-684.
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