Testosterone Propionate, Strength : 100mg/ml

Testosterone propionate is simply testosterone with the propionate ester bound it's chemical structure. The 'propionate' is propionic acid, but once bound to testosterone it is known as an ester bond (or ester linkage). Propinoic acid is bonded to the 17-beta hydroxyl group on the testosterone structure. Esterified anabolic steroids are more fat soluble, and release slowly from the injection site. The main reason for the increased half-life and release rate is because once testosterone propionate enters the bloodstream, enzymes work to break the bond between the ester and the testosterone, which takes a varying amount of time - depending on which ester is used. In the end enzymes remove the ester, and what is left is pure testosterone which is free to do its work in the body. Testosterone alone with no ester bonded to it has a half-life of approximately 2 to 4 hours. When the propionate ester is bonded to it, the half-life of testosterone extends to about 4 and a half days.
Testosterone promotes nitrogen retention in the muscle - the more nitrogen the muscle holds the more protein it can store, and the bigger it gets. Testosterone also increases the body's igf-1 levels. Igf-1's principal role is to coordinate growth and metabolism. Igf-i is highly dependent on growth hormone to complement it's growth promoting activity.