Testosterone is responsible for the normal growth and development of the male sex organs and for the maintenance of the secondary sexual characteristics. The drug can affect the growth of the prostate, testis, seminal vesicles, penis and scrotum and also is important for body growth. Even though testosterone is an androgenic hormone, it does posses anabolic properties. Its use has been shown to promote protein synthesis and a positive nitrogen balance in the presence of a rich calorie diet.
Testosterone also has the ability to cause a mild increase in the production of red blood cells by stimulating the synthesis of EPO from the kidney. This results in an increase in the red blood cells and hence an increase in the oxygen carrying capacity.
When testosterone is taken for prolonged periods, it inhibits the release of Gonadotropins from the pituitary gland through a negative feedback mechanism. At large doses, it can even inhibit spermatogenesis.
Testosterone propionate is released much faster after an intramuscular injection and stays in the body for up to 48-72 hours. It can be detected the urine for a lot longer period. The formulation comes as an esterified preparation of testosterone which is only meant to be administered by an intramuscular injection. The esterification of the testosterone increases the duration of action of the testosterone. The preparation comes in a colorless to mild yellow suspension of sesame oil. There are many athletes who complain that injection of testosterone propionate into the buttock area is painful. This pain may be due to injection of large amounts of the drug or the development of an abscess. It is best to use a low volume of the drug for injection and rotate to the site to prevent abscess formation.
The recommended dose of testosterone propionate for the novice bodybuilder is about 25 mg once a week. There are others who start off at 50-100mg/week. And yet there are others who combine the various testosterone formulations in a cocktail. The duration of testosterone treatment should be limited to 4-6 weeks to allow for the hypothalamic-pituitary axis and testes to recover.
During the washout phase of the drug, many athletes take Nolvadex ( tamoxifen) to prevent the estrogenic side effects of the testosterone.