Anabolic/androgenic steroids are generally well tolerated by the renal system. These drugs are largely excreted from the body through the kidneys, although there is no inherent strong toxicity in this process. In fact, there are many instances in which these drugs may be used as supportive treatment in patients with compromised kidney function. For example, anabolic steroids have been prescribed to increase the production of red blood cells in patients with anemia related to various forms of kidney disease. They have even been used as general anabolic (lean body mass) support, and to treat hypogonadism, in patients undergoing dialysis. While care must be taken with such patients, therapy may often be conducted very safely. In otherwise healthy individuals, clinical renal toxicity caused by the short-term administration of anabolic/androgenic steroids is unlikely.
There have been isolated reports of severe kidney damage in steroid abusers. For example, a handful of individuals have developed Wilms’ Tumor (nephroblastoma), which is a rare form of kidney cancer usually found in children. Its appearance in adult steroid users is suspect, but not conclusive evidence that drugs were the actual cause. There have also been isolated reports of renal cell carcinoma in steroid abusers. Since this is the most common form of kidney cancer, however, conclusive links are again difficult to draw. There have additionally been case reports of combined liver and renal failure with steroid abuse. In these cases kidney failure may have been subsequent to steroid-induced liver toxicity, as cholestasis (bile duct obstruction) is known to cause acute tubular necrosis and renal failure.
The use of anabolic/androgenic steroids in supratherapeutic doses may slightly impair immune system functioning, reducing an individual’s resistance to certain types of infection. In one study, steroid abusers were shown to have lower serum levels of IgG, IgM, and IgA immunoglobulins (antibodies) compared to bodybuilding controls, consistent with immunosuppression. Although this may logically increase the chance of contracting certain types of illness, Kidney health should be a concern for long-term steroid-using bodybuilders and power athletes. To begin with, excessive resistance training can produce some strain on the renal system. A condition called rhabdomyolysis is caused by the extreme damage of muscle tissue, which releases myoglobin and a number of nephrotoxic compounds into the blood. In high levels this can damage kidney tissue and even cause renal failure. There have been rare case reports of severe clinical rhabdomyolysis in bodybuilders, both with and without mention of steroid abuse. Steroid use may also cause hypertension, which can lead to kidney damage. While anabolic/androgenic steroids are generally not regarded as direct kidney toxic drugs, they may be used to support a lifestyle and long-term metabolic state characterized by extreme training, heightened daily muscle protein turnover, and elevated blood pressure. Over time this may compromise kidney health. Regular monitoring of kidney function is recommended.
Wlliam Llewellyn (2011) - Anabolics