Is the shortest-estered testosterone steroid. It’s an injectable compound with a slower rate of release than un-esterified Testosterone, but a faster rate of release than all the rest of esterified testosterones.There are some advantages and disadvantages to the short acting ester. The major disadvantage is that users have to inject Testosterone Propionate at minimum every other day throughout the cycle to get proper results. The advantages, however, are easier control and prevention of potential side effects. Also because there is less ester per vial, there is more actual testosterone per injection, which produces better results. The Propionate ester expands Testosterone’s half-life to about 4 and a half days.
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.
Domestic USA Testosterone Propionate