Testosterone enanthate is a slow-acting, long chain ester. It is formulated as an oil-based injectable testosterone compound, and is commonly prescribed for the treatment of hypogonadism-related symptoms. It is very similar to testosterone therapy cypionate.
Testosterone enanthate first appeared in the U.S. prescription drug market during the early 1950s, as Delatestryl by Squibb. It was sold and purchased several times over the years, most notably to Mead Johnson, BTG, Savient and, in December 2005, Indevus. Testosterone enanthate is most prominently featured in a hybrid blend with testosterone propionate under the brand name Testoviron, which has been produced by Schering AG in Germany for more than 50 years.
Testosterone enanthate is testosterone injections that has been esterified with enanthic acid; it has a half-life of ~8–9 days, which is the longest half-life of all common ester-based testosterone analogs. An uncommon testosterone such as Nebido (testosterone undecanoate) has a very long half-life of 3-months. Because it has longer carbon chain and hence a longer half-life, it only has to be administered every 8 or 9 days to maintain efficacious concentrations. Even though AAI Rejuvenation Clinic does not use the standard intramuscular needle tips that most clinics use, as ours are significantly more comfortable to utilize, most patients would still rather administer their testosterone as infrequently as possible.
Testosterone Enanthate Injection, USP provides Testosterone Enanthate Description, USP, a derivative of the primary endogenous androgen testosterone, for intramuscular administration. In their active form, androgens have a 17-beta-hydroxy group. Esterification of the 17-beta-hydroxy group increases the duration of action of testosterone; hydrolysis to free testosterone occurs in vivo. Each mL of sterile, colorless to pale yellow, solution provides 200 mg Testosterone Enanthate, USP in sesame oil with 5 mg chlorobutanol (chloral derivative) as a preservative.
Testosterone Enanthate, USP is designated chemically as androst-4-en-3-one, 17-[(1-oxoheptyl)-oxy]-, (17β)-. Structural formula:
Testosterone Enanthate – Clinical Pharmacology
Endogenous androgens are responsible for the normal growth and development of the male sex organs and for maintenance of secondary sex characteristics. These effects include growth and maturation of prostate, seminal vesicles, penis, and scrotum; development of male hair distribution, such as beard, pubic, chest, and axillary hair; laryngeal enlargement; vocal chord thickening; alterations in body musculature; and fat distribution.
Androgens also cause retention of nitrogen, sodium, potassium, and phosphorus, and decreased urinary excretion of calcium. Androgens have been reported to increase protein anabolism and decrease protein catabolism. Nitrogen balance is improved only when there is sufficient intake of calories and protein.