This is a story all about the racy subject of contraception. The female contraceptive pill has a history that dates back over half a century. The first pill approved by the US Food and Drug Administration came to market in 1957; and around sixty years later, about 100 million women worldwide now take the contraceptive pill. Generations of women have been empowered to take control of their fertility.
However, the search for a male alternative has thus far proved fruitless. The reason that the science behind the pill doesn’t work for men is that a male pill would need to target many millions of sperm rather than just one egg. Scientists have also had problems because a lot of drugs may contain the right elements, but they aren’t able to transfer from the blood to the testes and so they fail to have a contraceptive effect. Currently, the only drugs in clinical trials are contraceptives that counteract testosterone hormones, and it’s not always a good idea to mess around with hormones if you can help it.
But now, an international collaboration of scientists have used one of Diamond’s life sciences beamlines, I03, to develop a potential male contraceptive pill that works by targeting the specific protein responsible for sperm-cell production. The pill inhibits the aptly-named sperm-generating protein, bromodomain, whilst leaving the testosterone hormones untouched.
This could be a really important step forward for male contraceptive science. If it makes it to market, the male pill could reduce the rate of unplanned pregnancies, and thus have significant socio-economic effects on a global scale.
The pill uses a small-molecule inhibitor with the catchy name of JQ1. Once ingested, JQ1 effectively moves from the blood to the testes and inhibits bromodomain proteins. Mice treated with JQ1 were found to have a reduced sperm count, and their existing sperm were found to be less mobile and of lower quality. Despite this effect, their hormone levels remained normal. The effects of JQ1 were also found to be completely reversible. When the mice stopped being treated, their sperm count and quality returned to normal. Mating behaviours weren’t affected, suggesting that libido isn’t reduced by the male pill. And there didn’t appear to be any obvious effects in offspring produced during treatment or afterwards.
So, what does this mean? Well, if these studies are anything to go by, we may eventually have a male contraceptive pill akin to the female version, which can cross from the blood into the testes, impair sperm generation and produce a completely reversible contraceptive effect.
There are always things to consider when scientists are on the cusp of a discovery such as this. More research needs to be done into the long-term effects and the impact of JQ1 on different species. JQ1 is not selective at this stage, meaning that it needs to be refined so that the right proteins are affected. The research is still quite early on, but it’s certainly a significant step forward in the quest to develop the elusive male contraceptive pill. If nothing else, we certainly now know what proteins to target to control fertility. So look out bromodomain, science is on to you.
A brighter light for science