From the Guidelines
Testosterone has a beneficial effect on tendon and ligament health when present at normal physiological levels, but excessive amounts can lead to structural weaknesses and higher injury rates. The current evidence on the effects of testosterone on tendons and ligaments is largely based on its role in muscle growth and repair. Testosterone increases collagen synthesis, which strengthens tendons and ligaments by improving their structural integrity 1. It also enhances the production of growth factors like IGF-1, which promotes tissue repair and regeneration. Additionally, testosterone increases protein synthesis throughout the body, including in tendons and ligaments, helping maintain their strength and elasticity. However, it is essential to note that supraphysiological levels of testosterone, such as those seen with anabolic steroid use, can paradoxically weaken tendons by altering their biomechanical properties, making them stiffer and more prone to rupture 1. This occurs because excessive testosterone can cause disproportionate muscle growth that outpaces tendon strengthening, creating imbalances that increase injury risk. Key points to consider include:
- Normal physiological levels of testosterone are beneficial for tendon and ligament health
- Excessive amounts of testosterone may lead to structural weaknesses and higher injury rates
- Testosterone replacement therapy should aim to maintain appropriate hormone levels to optimize connective tissue health and function
- Athletes and individuals on testosterone replacement therapy should be aware of the potential risks and benefits of testosterone on tendon and ligament health. Overall, the evidence suggests that testosterone plays a crucial role in maintaining the health and function of tendons and ligaments, but its effects can be detrimental if present in excessive amounts.
From the Research
Effects of Testosterone on Tendons and Ligaments
- Testosterone can enhance tendon stiffness due to an enhanced tendon collagen turnover and collagen content 2
- The effects of testosterone on tendons and ligaments are not fully elucidated, but it is known that testosterone can enhance tendon collagen synthesis rate 2
- In men, testosterone has been linked to a reduced responsiveness to relaxin, which can affect tendon and ligament health 2
- There is no direct evidence on the effects of testosterone on tendons and ligaments in the studies 3, 4, 5, and 6, but these studies discuss the overall benefits of testosterone on muscle mass, bone density, and body composition, which can indirectly affect tendon and ligament health
Comparison of Testosterone Effects
- The effects of testosterone on tendons and ligaments are specific to men, and the differences in injury risk between men and women are likely due to sex hormonal differences 2
- Estrogen, present in women, can enhance tendon collagen synthesis rate, but high concentrations of estrogen can also enhance the risk of injuries due to reduced fibrillar crosslinking and enhanced joint laxity 2
- Testosterone therapy can improve bone mineral density and bone architecture, which can indirectly affect tendon and ligament health 3
- Testosterone supplementation can also improve body composition by reducing body fat mass and increasing lean body mass, which can affect tendon and ligament health 3