Not tonight, darling

A headache is one reason an effective male birth control injection has been rejected

Arecent study looking at the effectiveness of a male contraceptive injection was abandoned after the men taking part reported increased incidences of acne (nearly half), mood disorders (more than a fifth) and raised libido (more than a third).

There were 320 men in the study and a total of 1491 adverse events were reported. Those overseeing the trial regarded these side effects as more significant than the fact that the contraceptive injection appeared to work well in reducing the production of sperm.

Many women will feel these side effects are minor compared with those of the female contraceptive pill — and they’re right.

This raises the question: Why is it so hard to make a male contraceptive? If the plug has been pulled on this one because of side effects, would the female contraceptive pill make it to market if it were released today?

On the face of it, regulating fertility in men should be the more obvious choice. Sperm are produced constantly, not in cycles as eggs are in women. So, barring any underlying health problems, men are always fertile. The biology of sperm production is well-known, as is how to block it.

The study was exploiting the wellestablished relationship between testosterone — the hormone that gives men their male characteristics — and sperm production. By giving men synthetic testosterone along with a hormone called progestogen, similar to the hormones usually found in the pill, sperm production in the testes is reduced dramatically.

Before the study was halted, the researchers from Martin Luther University observed that pregnancy rates fell to an equivalent of 1.5 babies conceived by every 100 couples. Compare this with the pregnancy rate of nine babies per 100 couples for women using the combined pill, and the development of a male contraceptive seems like a no-brainer.

Yet we are no closer to a viable male contraceptive. Women are left in charge of their fertility and bear the brunt of contraceptives’ side effects. Many women may view the side effects as the lesser evil com- pared with an unplanned pregnancy, and many may also question whether leaving the responsibility for contraception to men would work.

But the side effects of the male “pill” could have an unlikely benefit. With both partners actively taking contraceptives and sharing an understanding of the side effects, a joint sense of responsibility would be established. Also, if one partner needed to take a break from their contraceptive, the other could start taking theirs, sharing the effect of those side effects.

Women have been taking the pill and enduring the side effects since the early 1960s. Looking at the original trial results from 1956, it’s hard to see how the contraceptive pill ever made it to market.

The first large-scale human trial was conducted in Rio Piédras, a Puerto Rican housing project. The women taking part received little information about the pill, partly because there was little to give and partly, perhaps, because none of the people running the trial thought it necessary. Such were clinical trials in the 1950s. Women reported side effects including headaches, dizziness, nausea and blood clots, but these were largely dismissed.

Since then, thankfully, the pill has been refined and modified, and is now taken by about 225-million women worldwide. It unquestionably changed female sexual freedom, allowing women greater control over when to have children. In 2012, British women voted the pill their favourite invention of the past century — ahead of leisure devices such as the internet and television.

So why hasn’t big pharma ploughed more resources into a male “pill”? Part of the problem appears to be the very success of female contraceptives, from which many pharmaceutical companies make big profits, so there is little desire to take focus away from them. It also seems there is no universal desire by men for such a pill.

Until there’s more demand from men for a pill of their own, the responsibility will be left to women.

In light of the enormous benefits the contraceptive pill has brought to women and their sexual health, it would be hard to imagine a world without it.

But perhaps we should also be asking why, even in the 21st century, the idea of a man taking a contraceptive pill remains such a big deal.