The use of anabolic steroids can cause testicular atrophy, commonly referred to as “shrinking of the testicles” or “small balls.” This happens for a couple of physiological reasons:
- Negative Feedback on the Hypothalamic-Pituitary-Gonadal Axis (HPG axis): The body has a system to regulate the production of testosterone, which involves the hypothalamus, the pituitary gland, and the testes. When steroids are introduced into the body, they increase the level of testosterone-like effects. This high level is detected by the hypothalamus, which then reduces the release of gonadotropin-releasing hormone (GnRH). This in turn decreases the production of luteinizing hormone (LH) by the pituitary gland, and LH is necessary for stimulating the testes to produce testosterone. With lower LH, the testes reduce their normal function of testosterone production.
- Lack of Leydig Cell Stimulation: Leydig cells in the testes are responsible for producing testosterone when stimulated by LH. If the body is getting a signal that there is enough testosterone (or more) circulating due to the intake of steroids, it will not stimulate these cells to produce testosterone. Without this stimulation, the Leydig cells decrease in activity and the testes can shrink.
When the testicles shrink, it can lead to reduced sperm production and fertility issues, among other hormonal disruptions. This is one of the reasons why the use of steroids without medical supervision is considered risky and is often discouraged. The body’s endocrine system is delicate and finely tuned, and introducing external hormones can lead to long-term and sometimes irreversible effects.
What causes men to have a low testosterone?
Fertility is the goal.