Anabolic steroids are synthetic versions of the hormone testosterone, commonly used to alter body appearance or increase physical performance. While the physical changes that come with their use might be obvious, you might not understand the impact they have on your fertility. Steroid use can disrupt the hormones that control sperm production, shrink the testes and lead to temporary or long-term male infertility. Here’s how steroids affect male fertility and why these effects can last long after someone stops using them.
What are anabolic steroids?
When people talk about ‘steroids’ in boys and men they’re generally referring to testosterone (the main male sex hormone, or ‘androgen’ in our bodies) and/or synthetic (human-made) versions of testosterone (there are a lot of them), often in the context of performance- and image-enhancing drugs (PIEDs).
Although steroids were first used for performance enhancement by weightlifters and then other competitive athletes, use is now far more widespread throughout our communities and seems to be driven more by image concerns than by a desire for enhanced performance.
Influencers from the manosphere are aggressively promoting the use of steroids for looksmaxxing, longevity, rejuvenation and sexual function. But at what cost?
What are the health risks of steroid use?
For something that is used for improving appearance, steroids cause plenty of potentially unattractive effects. Bacne, stretch marks, balding, excessive body hair, increased sweating and gynaecomastia are all consequences of steroid use.
Beyond cosmetic and aesthetic concerns, some of the behavioural effects of steroid use are pretty ugly. Aggression, impulsivity and agitation are not very attractive personality characteristics. Other psychological effects can be much more serious. Anxiety, depression, self-harm and suicide are all increased by steroid use.
In addition to these effects on mental health, severe physical health problems (like cardiovascular disease, liver dysfunction, kidney failure and cancer) are caused by steroid use and can be fatal.
It’s probably not a coincidence that professional wrestlers (whose steroid use for achieving idealised hypermasculine bodies is infamous) have death rates from cardiovascular disease that are 15-times higher than for the general population, and for cancer more-than-6-times higher.
Just about everyone who uses steroids experiences some sort of undesirable effect, but it’s a bit of lottery as to which one(s) will affect each individual user because not all of the negative effects are experienced by everyone. That makes it easy for people using steroids to dismiss the negative effects, by thinking “it won’t happen to me”, or by dismissing the long-term risk of serious health problems in favour of the short-term gains they expect to achieve. This sort of thinking might be made easier if people don’t see themselves as using steroids to the same extent as pro wrestlers.
There is one effect of steroids that is experienced by just about everyone who uses them, which occurs quite quickly and takes a long time to go away: testicular atrophy – literally, wasting away of the testes.
How do steroids affect male fertility?
Taking testosterone tells your body and brain to switch off its own production of the hormone. This is because of the hypothalamic-pituitary-gonadal axis, which works hard to keep your body’s hormones at a healthy level.
Maintaining the balance between all the things going on in your body is critical for health and wellbeing, so there are built-in feedback mechanisms that monitor and respond to changes – sort of like thermostats or cruise controls. Here’s a more in-depth explanation.
The testosterone level in your blood is monitored by the hypothalamus (a region in the brain). If your level of testosterone is too low, cells in the hypothalamus release gonadotrophin-releasing hormone (GnRH), which then acts on cells in the pituitary gland to cause the release of follicle-stimulating hormone (FSH) and luteinising hormone (LH) into the bloodstream. LH stimulates the Leydig cells in the testes to make testosterone. FSH (together with very high levels of testosterone from the nearby Leydig cells) stimulates the Sertoli cells in the testes to make sperm. Testosterone from the Leydig cells eventually enters the bloodstream, and when the hypothalamus detects a rise in the blood testosterone level, it stops releasing GnRH. The testosterone level in the blood (monitored by the hypothalamus) gradually falls, eventually stimulating GnRH release by the hypothalamus (and the cycle starts again).
When people take steroids, the hypothalamus detects the higher-than-normal levels and stops releasing GnRH. Without GnRH, release of FSH and LH from the pituitary is drastically reduced, so the testes stop making testosterone and sperm.
Animal experiments show that without stimulation from FSH and LH there is cell death of Leydig cells and Sertoli cells, and other cells in the seminiferous tubules where sperm are produced. In men using steroids, this wasting away of the testes reduces their size by about half and it takes years for testicular size to return to normal.
The negative effect of steroids on testicular function lasts a long time but they occur quickly. Sperm count begins to fall 2 weeks after starting to take steroids (sperm movement, shape and survival fall after 1-to-2 months), and is at its lowest after 2-3 months. These changes occur far more quickly than peak changes in muscle mass and strength, which occur after 6-12 months. Like changes in testicular size, the negative effects on sperm production and quality can take years to recover, with longer periods of steroid use resulting in longer recovery times.
The effects of steroids on the testes explain why most men who use steroids are infertile, and why it takes at least a year to recover fertility after stopping use.
Testicular atrophy is probably the most common unwanted effect of using steroids, and the associated infertility can be “emasculating, distressing and isolating”.
Do steroids reduce sperm count?
Yes. Sperm count begins to fall two weeks after starting to take steroids (sperm movement, shape and survival fall after one-to-two months), and is at its lowest after two to three months. These changes occur far more quickly than peak changes in muscle mass and strength, which occur after six to 12 months.
How long is fertility impacted by steroids use?
The effects of steroids on male fertility occur quickly but last a long time. Like changes in testicular size, the negative effects of anabolic steroids on sperm production and quality can take years to recover, with longer periods of steroid use resulting in longer recovery times.
What should you do if you’re using steroids but want to start a family?
Men using anabolic steroids who want to conceive should stop using steroids and see their GP early, because sperm recovery can take many months and might need medical support.
You shouldn’t try to fix the problem with “stacking”. Self-medicating can further harm your health and miss treatable health problems that need proper work‑up and monitoring.
Is your partner using steroids, and you’re worried about infertility?
Tim Moss
Healthy Male Health Content Manager
Dr Tim Moss has PhD in physiology and more than 20 years’ experience as a biomedical research scientist. Tim stepped away from his successful academic career at the end of 2019, to apply his skills in turning complicated scientific and medical knowledge into information that all people can use to improve their health and wellbeing. Tim has written for crikey.com and Scientific American’s Observations blog, which is far more interesting than his authorship of over 150 academic publications. He has studied science communication at the Alan Alda Centre for Communicating Science in New York, and at the Department of Biological Engineering Communication Lab at MIT in Boston.
