Testosterone isocaproate is primarily used in hormone replacement therapy (HRT) for men who have low levels of testosterone, a condition known as hypogonadism. It helps restore normal testosterone levels, improving symptoms such as fatigue, low libido, and muscle loss. Additionally, it is utilized in the treatment of certain types of breast cancer in women, where it helps counteract the effects of estrogen. In the field of sports medicine, it is sometimes misused as an anabolic steroid to enhance muscle mass and athletic performance, though this is illegal and poses significant health risks. The compound is typically administered via intramuscular injection, ensuring a slow and sustained release into the bloodstream.