Steroids and Sterility: A New Study


4 minute read

Many men choose a structured workout routine to stay in shape, building muscle and cutting fat – all in a quest to sculpt a more attractive figure while also boosting overall health.

And it doesn’t hurt that potential partners tend to take note when a man gets serious about working out. Physical beauty certainly isn’t the only factor that people look for when searching for a mate, but it’s almost always where they begin.

To enhance one’s chances of maximizing a first impression, some men decide to use anabolic steroids to enhance the benefits of lifting weights. These substances have long been the focus of oversight by governing bodies in professional sports, where the drugs have been banned, with some users forfeiting awards and titles that they won years before their drug use was discovered – even when, in the case of cyclist Lance Armstrong, his steroid of choice turned out not to be ineffective.

The link between steroids and fertility

Now, though, a new study says that the health consequences of using anabolic steroids include a 90 percent chance of damage to a man’s fertility. The information can be found in a letter published in the Journal of Internal Medicine (paywall site).

The co-authors of the letter, Dr. James Mossman at Brown University in Providence, Rhode Island and Professor Allan Pacey at the University of Sheffield (Professor Pacey is also a member of Legacy’s advisory board), say that the risks posed to fertility by steroids are similar to those brought about by medications designed to prevent hair loss, specifically finasteride, which alters the manner in which testosterone is metabolized.

Finasteride has also been known to reduce sperm counts as well as hamper sperm motility (swimming ability). Another side effect of taking the drug is erectile dysfunction.

The new discovery, dubbed an “evolutionary paradox” by an article published in BioNews 1000, is now known as the Mossman-Pacey paradox – so called because men who take them in order to become more attractive wind up harming their chances of starting a family.

Dr. Mossman first took note of the link between steroid use and impaired fertility when he was studying to obtain his doctorate from the University of Sheffield.

“I noticed some men coming in to have their fertility tested and these guys were huge. They are trying to look really big, to look like the pinnacles of evolution,” he said. “But they are making themselves very unfit in an evolutionary sense, because without exception they had no sperm in their ejaculation at all”.

Professor Pacey was quoted by as saying, “Isn’t it ironic that men go to the gym to look wonderful, for the most part to attract women, and inadvertently decrease their fertility”.

In speaking to the BBC, Professor Pacey commented, “The irony is one thing, but I think the key message is for fertility patients. It keeps cropping up in clinics and the message is not getting out to young men that it's a problem and a bit of info could save them a lot of heartache.”

Knowing the direct effects

Anabolic steroids, which are synthetic versions of testosterone, work by tricking the brain’s pituitary gland into believing that a man’s testes are working overtime. As a result, the glands respond by ceasing the production of a pair of hormones – known as Luteinizing Hormone (LH) and Follicle-Stimulating Hormone FSH – which happen to be the critical hormones responsible for the creation of sperm.

According to Professor Pacey, roughly 9 in 10 anabolic steroid users “are likely to become sterile”. He went on to say that, while baldness is less predictable, sales of hair loss-prevention products “are going through the roof and that makes it an increasingly common problem”.

Dr. Mossman pointed out that taking vanity-based medications could wind up turning a man into something of an “evolutionary dud”. It is not on par with, say, the displaying of a peacock’s tail, which has the effect of making males more desirable to females, while also increasing the possibility of passing along genes to succeeding generations.

While it is true that some bird species participate in cooperative breeding – where some don’t have their own offspring but instead help raise descendants of relatives – Dr. Mossman says that humans are likely the only creatures known to harm their own fertility by trying to make themselves attractive to the opposite sex.

All the more reason to proactively store your assets now – before taking up a steroid-enhanced exercise regimen, or even resorting to medications to limit hair loss.