‘Rub-on’ male contraception gel to be trialled in UK – and you don’t rub it where you think you would

A rub-in contraceptive gel that could prevent sperm production in men is going to be trialled, marking the largest effort by US researchers to test a hormonal form of male birth control.

The new gel encompasses two synthetic hormones: progestin and testosterone. The former reduces the testosterone levels in the testes, enough to stop sperm being made. The latter compensates for this by keeping testosterone levels balanced in the rest of the body.

Contrary to assumption, the gel isn’t rubbed into the genitals. Instead, men will need to rub half a teaspoon of the gel onto their upper arms or shoulders every day.

The gel has been in development for several years. In 2012, researchers behind the project at the US National Institute of Child Health and Human Development trialled the pair of hormones as separate gels over a six-month study. Sperm counts dropped to less than one million per milliliter (normal sperm count ranges between 15 and 200 million per milliliter).  

Trials with the new, combined gel will cover more than 400 couples in the US, UK, Sweden, Italy, Kenya and Chile. Those involved in the study will initially use the contraception for at least four months while their partner is on female contraception. Once the male subjects’ sperm count has lowered to less than one million, their partner will stop their contraception, leaving the gel as the only birth control for a year.

“It’s not a lot of effort. It’s just remembering to use it every day,” Diana Blithe, program director for contraception development at the National Institute of Child Health and Human Development, told Technology Review.

If the trial is a success, it could signal a crucial step towards the creation of a way for men to regulate their own fertility. Historically, however, the path towards a male ‘pill’ has not run smoothly. Here’s a rundown of previous efforts, and the social and scientific barriers facing efforts to create a new type of contraception for men.

Male contraceptive pills, injections and gels: What research has already been done?

Currently, the only forms of contraception available to men are condoms and a vasectomy. There’s also the pull-out method, but this isn’t far from reliable. In the latter-half of the 20th century, the combined oral contraceptive pill (‘The Pill’) became publicly available for women, leading to studies around a similar pill-based contraception for men. There have been a number of different medications developed, but so far none has made it to market.

The largest recent study took place in Europe between 2008 and 2012, with participants injecting hormones at two-month intervals to suppress sperm production. It managed to do this successfully, and effectively prevented pregnancy in female partners, but was stopped on the recommendation of an outside panel due to serious side effects to participants’ mental state – which had, in one case, led to suicide.

Previous to this, there have been handfuls of abandoned and slow-burning studies. Most of these have centred on hormone-based treatments, although non-hormone studies do exist such as study from the University of Kansas into the use of a drug called gamendazole, which has been shown to reversibly stunt the development of sperm in rats. Another non-hormone idea from King’s College London involves phenoxybenzamine, used to treat high blood pressure. The pill can produce a semen-free orgasm, although has only been tested on animals.

One of the most promising developments in recent years has been a product called Vasalgel; a gel injected into the vas deferens (the tube that carries the sperm from the testes), which acts as an effective barrier. If widely adopted, it would be a vague equivalent to the coil for women. The procedure is reversible, as the gel can be flushed out with a sodium bicarbonate solution. So far, this has been successfully tested in primates, and the non-profit organisation behind the study – the Parsemus Foundations – says it wants to start human tests as soon as funding is secured.

Why don’t we have a male pill yet?

There are both scientific and social reasons for a lack of movement in male contraception. Scientifically, preventing the daily production of hundreds of millions of sperm is more complicated than stopping the release of a single egg every month. Socially, past failures and a lack of enthusiasm from pharmaceutical companies means funding for expensive clinical trials is scarce.

A Chinese trial into an injectable hormonal contraceptive, for example, was found to be successful, but scuppered when the company manufacturing the drug, Zhejiang Xian Ju Pharmaceutical, never went forward with testing or regulatory approval.

As well as funding issues, there’s also the underlying issue of whether men would embrace a male ‘pill’ at all. A 2010 worldwide study found that 25% of men would consider the use of hormonal contraception; a figure that is far from the majority, but does suggest there is a place for medical-based contraception as an option. ‘The Pill’ was a revolution in terms of women having greater control over their own bodies, but there’s the sentiment men may feel more psychologically distant from pregnancy, and therefore less inclined to momentarily switch off their fertility.  

All of these attitudes can change, and if one of the of the developing approaches comes to fruition, it could do a great deal in preventing unwanted pregnancies. That said, the current state of research and development means it will ultimately be several years before we see any sign of a publicly-available male ‘pill’.