Testosterone is an anabolic steroid, most commonly found in oil-based injectable solutions, which is divided into several esters – types, and some of them are Cypionate (Testosterone Cypionate) and Enanthate (Testosterone Enanthate).
Examining these two types of testosterone and their effects: The qualities of Enanthate and Cypionate are that these are the slowest injectable testosterones. They hardly differ from each other. In the United States, Cypionate is widely used and is the preferred anabolic injectable steroid, while in Europe, Enanthate is more commonly found in systems for increasing muscle mass and strength during the primary period of athletes in bodybuilding and other sports disciplines.
Testosterone (Cypionate) is the slowest testosterone: Testosterone Cypionate is an injectable anabolic steroid available most commonly in 1 ml ampoules containing 200 mg/ml of the substance Testosterone Cypionate. Each milliliter of the solution contains 200 mg of Testosterone Cypionate, 0.2 ml of Benzyl Benzoate, 560 mg of Cottonseed Oil, and 9.45 mg of Benzyl Alcohol (as a preservative).
Structural formula of Cypionate: Testosterone Cypionate in clinical pharmacology: Endogenous androgens are responsible for the normal growth and development of male sex organs and the maintenance of secondary sexual characteristics.
Effects: These effects include the growth and maturation of the prostate, seminal vesicles, penis, and scrotum; the growth of body hair in men, such as beard, pubic area, chest, and axillary hair; enlargement of the larynx, thickening of the vocal cords, and changes in muscle mass and fat distribution. Preparations in this class induce the retention of nitrogen, sodium, potassium, and phosphorus and decrease the excretion of calcium; thus, additional calcium intake is required if the cycle involves high doses of Testosterone Cypionate. Androgens have been reported to increase protein anabolism and decrease protein catabolism. The nitrogen balance improves only when there is adequate caloric and protein intake.
Androgens are responsible for the rapid growth during adolescence and the eventual cessation of linear growth, caused by the fusion of epiphyseal growth centers. In children, external androgens accelerate linear growth rates but can lead to excessive bone maturation. Long-term use can lead to the fusion of epiphyseal growth centers and cessation of the growth process. Androgens are reported to stimulate the production of red blood cells by enhancing the production of the erythropoietin-stimulating factor.
Through exogenous administration of androgens, endogenous testosterone release is inhibited via feedback inhibition of the pituitary gland and luteinizing hormone (LH). In large doses of exogenous androgens, spermatogenesis may be suppressed through feedback inhibition of the follicle-stimulating hormone (FSH) in the pituitary gland.
There is a lack of substantial evidence that androgens are effective in fractures, surgery, recovery after illness, or functional uterine bleeding.
Pharmacokinetics: Testosterone esters are less polar than free testosterone. Testosterone esters in oil for intramuscular injection are slowly absorbed from the lipid phase; thus, Testosterone Cypionate can be administered at intervals of two to four weeks. Athletes using this preparation inject one to two ampoules per week, each containing 200 mg (a total of 400 mg) of Testosterone Cypionate.
Testosterone in plasma is 98 percent bound to a specific testosterone-estradiol binding globulin, and about 2 percent is free. Generally, the amount of this sex hormone-binding globulin in plasma determines the distribution of testosterone between free and bound forms, and the concentration of free testosterone determines its half-life.
About 90 percent of a dose of testosterone is excreted in the urine as glucuronic and sulfuric acid conjugates of testosterone and its metabolic acid; about 6% of the dose is excreted in the feces, primarily in the unconjugated form. Inactivation of testosterone occurs mainly in the liver. Testosterone is metabolized into various 17-keto steroids through two different pathways.
The half-life of Testosterone Cypionate when injected intramuscularly is approximately eight days.
In many tissues, the activity of testosterone appears to depend on its reduction to dihydrotestosterone, which binds to cytosolic receptor proteins. The steroid-receptor complex is transported to the nucleus, where it initiates transcriptional events and cellular changes associated with androgen action.