Sustanon-250 is a mixture of testosterone esters, similar to the natural male hormone testosterone, in an oil solution. Testosterone is produced in the male gonads and Leydig cells and is the main endogenous hormone required for the development of the male reproductive organs (prostate, seminal vesicles, penis and scrotum) and secondary sexual characteristics in men (male-pattern hair development and distribution, laryngeal enlargement ; change in tone of voice, body musculature and fat distribution).

In adult men, testosterone is essential for the functioning of the testes and epididymis, prostate and seminal vesicles, as well as maintaining libido, wellness, and erectile function.

Therapy of men with hypogonadism with Sustanon-250 leads to a clinically significant increase in the concentrations of testosterone, dihydrotestosterone, estradiol and androstenedione in plasma, as well as to a decrease in the concentration of sex hormone binding globulin (SHBG); LH and FSH concentrations are restored to normal values.

Therapy with Sustanon-250 reduces the clinical symptoms of testosterone deficiency. In addition, bone mineral density and muscle mass increase, and body weight decreases in obese patients. In the course of treatment, sexual functions are normalized, including erectile function and libido. When using the drug, plasma concentrations of HDL, LDL are reduced; the content of hemoglobin and hematocrit increases, while there is no clinically significant change in the activity of "liver" enzymes and prostate specific antigen (PSA). Therapy with the drug can cause an increase in the size of the prostate gland, while no dysfunction is observed. In men with hypogonadism and concomitant diabetes mellitus, the use of androgens improves insulin sensitivity and / or decreases plasma glucose concentrations.

The use of androgens in transgender women promotes masculinization.