How Steroids, Testosterone Supplements Can Decrease Fertility in Men

The connection between testosterone and infertility

As Dr. Brian Levine, founding partner and practice director of CCRM New York, puts it, “taking testosterone is almost male contraception.”

The use of testosterone or anabolic steroids to gain muscles mass, and thus appear more fertile, while actually increasing one’s likelihood of infertility, is now known as the Mossman-Pacey paradox, named after the two researchers who first described it, as the BBC and other outlets recently reported.

It pits two different points of a man’s search for a mate: the short-term gains of appearing more attractive to females while enduring potential long-term damages to their ability to reproduce.

That’s particularly about the type of steroids used to grow muscles to nearly Herculean size. But it’s also in the small daily doses of products meant to increase energy and improve libido.

Dr. Katherine McKnight, a reproductive endocrinology and infertility specialist at CCRM Houston, says she sees a large population of couples with male infertility solely due to testosterone use, as high doses of testosterone decrease a man’s sperm count significantly.

“There is a large focus in men’s health today on combating fatigue and increasing energy and libido,” she told Healthline. “Unfortunately, hormonal medications, specifically testosterone and its derivatives, are used to manage these symptoms.”

While some effects of these medications that alter testosterone can be reversed, experts warn it’s better to avoid anything that messes with your body’s testosterone levels because it can develop a tolerance.

Basically, the more the brain senses testosterone in the blood, the less it signals for the testes to make on their own.

Paul Jenkins, sports coach and founder of the supplement company DNA Lean, has two decades worth of experience working with athletes, namely amateur and professional competitive bodybuilders, “of which all have used steroids.”

Balding is another common side effect of testosterone use, which is why so many bodybuilders shave their heads.

Jenkins says when external testosterone is introduced into a man’s body, it breaks the body’s natural cycle, causing the testes to stop their production of natural testosterone, resulting in testicular atrophy.

“As you can imagine, shrunken testicles are largely infertile,” Jenkins told Healthline. “When testosterone treatments are ceased, the testes will be shut down and testosterone levels will plummet. This results in erectile dysfunction and infertility, along with a myriad of other symptoms.”

The worst part? Once steroids use is stopped, balding remains.

What to consider before taking testosterone-boosting supplements

Besides short-term — that could become long-term — effects on sexual performance, researchers don’t yet know what additional effects altered testosterone may have on the other functions of the body, such as regulating heart and bone health.

Levine says potential patients should review all of their medical conditions with their doctor, as these medications and supplements can impact other organs besides reproductive ones, such as the liver or kidneys, as well as have dangerous interactions with other medications.

“Once understanding the risks, the patients should know that they may have issues with sexual performance, weight gain/loss, and fertility,” he said.

But experts also warn about the messaging that comes with these supplements and medications, as the loss of hair, libido, and energy are a natural part of aging that are best combatted with a healthy diet and exercise and sleep routines.

Some of these products are marketed by male-centered media personalities with long-form messages that adhere closely to traditional masculine stereotypes. This kind of messaging-to-marketing pipeline, experts say, can have an effect on the average media-consuming male’s long-term health and well-being.

“These media personalities reinforce a stereotype among men that strength and virility are paramount to a man’s sense of self,” McKnight said. “This often leads men to seek medications for thinning hair, lower libido, fatigue, and decreased muscle mass.”

And that can be unhealthy.

The rise in male infertility

There have been varying reports in recent years about the decline of male fertility. One article in GQ went as so far as to insinuate that humans are on path of being threatened as a species.

A 2017 review of studies published in Human Reproduction Update examined available studies on sperm count in men from North America, Europe, and Australia and found they had dropped more than 52.4 percent from 1973 to 2011, “with no evidence of a ‘leveling off’ in recent years.”

“These findings strongly suggest a significant decline in male reproductive health, which has serious implications beyond fertility concerns,” the researchers concluded.

While it’s nearly impossible to pinpoint a single factor contributing to the rise in male infertility, some experts like Levine suggest it isn’t on the rise, but experts are now better at diagnosing and categorizing it.

“We are much more sensitive to abnormalities and we are much more eager to treat abnormal numbers with treatments like insemination and [in vitro fertilization],” he said.

McKnight argues the rise in male infertility has multiple factors, including that people now are generally waiting until later ages to attempt to conceive a child.

“Sperm quality decreases with age, though actual sperm counts may stay the same,” she said.

There is, of course, the increase in the use of testosterone and other hormone-modifying drugs, which McKnight says has contributed to the decline in male fertility.

In Houston, where McKnight works — as well as across the rest of the United States — radio and billboard advertisements that promise men more energy and increased muscle mass are more common.

“Unfortunately,” she said, “the reproductive risks of some of these medications is not completely understood by the consumer.”

Before taking any supplement or drug that promises to increase energy, improve libido, or increase muscle mass, talk with your doctor to make sure you understand the reproductive risks associated with their use. Natural, safer options may be available to help you reach your goals in a healthier way.