Nandrolone decanoate shares the actions of endogenous androgens such as testosterone. Exogenous androgens such as nandrolone decanoate promote protein anabolism and stimulate appetite which results in a reversal of catabolic processes and negative nitrogen balance. Increases in lean body mass in patients with cachexia (e.g., malnourished dialysis patients) and decreased bone resorption and increased bone density in patients with osteoporosis are often noted. Blood glucose, erythrocyte production, and the balance of calcium are also affected by androgens. Increased erythrocyte production is apparently due to enhanced production of erythropoietic stimulating factor. Patients with anemia associated with renal disease will have increases in red blood cell volume and hemoglobin after receiving nandrolone decanoate.
Since nandrolone decanoate has actions similar to endogenous androgens, administration of nandrolone decanoate has the possibility of causing serious disturbances of growth and sexual development if given to young children and causing unwanted adverse effects in women. Exogenous androgens suppress gonadotropin-releasing hormone, thereby reducing the gonadotropic function of the pituitary through a negative-feedback mechanism. This results in a reduction of endogenous testosterone, luteinizing hormone, and follicle-stimulating hormone. Exogenous androgens may also have a direct effect on the testes. Reversible increases in low-density lipoproteins (LDL) and decreases in high-density lipoproteins (HDL) also occur.