anabolic steroids and male fertility

The use of image and performance enhancing drugs is something that has been around for many years, most noticeably in the world of sport.


However, there is an even more concerning use of these drugs, and it appears that our younger generation are putting themselves in harm’s way just to look good without the slightest idea of what it’s doing to their testicles and sperm.  


With the polished and airbrushed images we are bombarded with on social media, it’s hard to avoid the image of the “perfect” man with his big biceps and toned body. It’s these images that are potentially leading younger men (typically aged 20 – 24) to seek out performance enhancing drugs to help them get that “love island” look. Yet this isn’t exclusively a young person’s problem with performance enhancing drug use being common among many gym goers of varying ages.


A report from the UK anti-doping body estimates that there are around 1,000,000 users in the UK and around 34% of gym users are aware of drug use within their gym.


What are these drugs?

The most common performance enhancing drugs used are anabolic steroids. To give them their full name they’re actually known as anabolic-androgenic steroids (AASs).


AASs are synthetic (man-made) substances which mimic the effects of testosterone, which is the most important androgenic hormone in the body and is responsible for the development of the male body, not only during puberty, but also during fetal development in the womb during the 6th and 26th week of pregnancy, where it is essential for the male sexual differentiation and development. During puberty, testosterone and dihydrotestosterone are helping with hair growth, muscle development, development of the penis, prostate, testicles, and the male phenotype in general including libido.


While the anabolic element of AASs promotes the use of energy to help build muscle mass and strength, the androgenic element of AASs mimics the effects of testosterone by latching on to androgen receptors within the body, thereby increasing muscle growth and development.


The use of AASs enhances muscle growth and increases energy, thereby improving athletic performance. Users of AASs will sometimes end up taking a concoction of other drugs such as insulin, diuretics and thyroxine to limit the negative affects AASs have on the body. The long-term health risks of these drug combinations can be significant.


Just to note, AASs are very different to corticosteroids which you may have had prescribed from your GP. Corticosteroids are typically prescribed to help with inflammation or suppress the immune system and act on the body in a very different way to AASs. Within this article we are purely focussing on AASs.


What are the side effects?

The side effects of AASs are well researched and well known and aren’t just limited to the physical body.

Physiological side effects include:

  • Baldness
  • Acne
  • Excessive body hair
  • Gynaecomastia (man boobs)
  • Liver dysfunction
  • Hypertension
  • Heart attack
  • Stroke
  • Fertility issues

Psychological side effects include:

  • Addiction
  • Depression
  • Aggression and violence
  • Decreased libido
  • Mood changes
  • Paranoia
  • Euphoria


The fertility effects.

AASs can have a serious impact on a man’s fertility. Testosterone plays a significant role in the development of the testicles, spermatogenesis, our libido and our ability to maintain an erection. Another important role of testosterone is its role within the pituitary–hypothalamus system. Testosterone provides negative feedback to the pituitary gland to regulate the hormones responsible for triggering sperm production. As testosterone increases it prompts the pituitary gland to decrease follicle stimulating and luteinising hormone production. Follicle stimulating hormone is directly responsible for stimulating the testicles into producing sperm so as it decreases with raised testosterone levels, sperm production drops.


Men who routinely use AASs are likely to experience the following in relation to their sperm:

  • Decreased testicular volume
  • Decrease in sperm count
  • Decrease in sperm motility
  • Increase in abnormally shaped sperm


Animal studies have shown that the number of Leydig cells within the testicles drops considerably as a result of AAS use. Leydig cells are the primary source of androgens and testosterone in men and are crucial for sperm production and spermatogenesis. Studies have shown that Leydig cell numbers do improve after AAS use stops, however numbers don’t always return to previously seen levels.


Further studies have also demonstrated that levels of spermatogenic cell death (apoptosis) increases with AAS use which is further exacerbated by physical exercise. So, those men who are using AASs and exercising are in effect increasing their sperm cell death considerably. 


In severe cases, men can experience a complete failure in sperm production resulting in azoospermia (no sperm in the ejaculate).


The long-lasting effects

Research has shown that in many cases where AAS use is stopped, sperm quality improves and returns to normal although this will take several months. However, there are cases when this doesn’t happen, and spermatogenesis doesn’t restart. In these cases, men will need further hormone treatment in an attempt to restart the hormone cycle and subsequent sperm production. Liken it to your car having a dead battery and you need a jump start!


In summary

Taking any kind of hormone therapy is a dangerous game! The mortality risk amongst men who take AASs is 4.6 times higher than those who don’t! Our bodies are finely tuned systems where any alteration in the balance of hormones can have serious knock-on effects. Adding in external (exogenous) hormones without medical indication and supervision is strongly discouraged. 


Although in many cases cessation of AAS use results in the return of healthy / normal sperm, there is the potential of lasting damage both to the testicles and other areas of the body which will result in the need for further medical treatment.


What is of serious concern is the use of these drugs among young men who aren’t likely to fully understand the long-term risks and are also less likely to be considering the impact on their fertility. We know that there is a significant gap in the education of young people around fertility and you can guarantee that they don’t fully understand the implications of AAS use on their sperm health, reproductive health and general health. 


If you are currently using AASs, you are encouraged to stop using them immediately. If you have been using AASs or are still using them, then we would encourage you to get a comprehensive fertility assessment including a semen analysis and blood hormone test. You may also want to consider seeing a Urologist / Andrologist to ensure you have been properly assessed.

If you’re experiencing signs of addiction and need help in stopping, then please contact your GP for advice and support.



Research reviewed

UKAD status report on IPEDs in the UK – 2019


El Osta R, Almont T, Diligent C, Hubert N, Eschwège P, Hubert J (2016); Anabolic steroids abuse and male infertility. Basic Clin Androl 26: 2