Testosterone Propionate is Testosterone with the Propionate ester bound to the Testosterone molecule. More specifically ‘Propionate’ is Propionic acid, but once bound to Testosterone it can be referred to as an ester bond. Esterified anabolic steroids tend to be more fat-soluble, thus allowing Testosterone to release slowly from the injection site. Once Testosterone Propionate enters the bloodstream, the bond between the ester and the hormone are broken down by enzymes which takes a varying amount of time depending on which ester is coupled with the Testosterone molecule. The ester bond is removed by enzymes, which results in pure Testosterone which is plays its role in the body. This also results in slower Testosterone release rates. Testosterone alone with no ester bonded to it possesses a half-life of approximately 2 – 4 hours. With the Propionate ester attached to it, the half-life of Testosterone is now extended to 2-3 days, providing a slower release and activity of the drug.
Testosterone possesses a moderate level of estrogenic activity, whereby it holds a moderate affinity to bind to the aromatase enzyme which is also the enzyme responsible for the conversion of Testosterone into Estrogen. Testosterone converts into estrogen on a 1:1 ratio. For every 100mg of Testosterone injected, 50mg converts to estrogen. A moderate level of aromatization is to be expected with Testosterone unless an aromatase inhibitor is incorporated such as Arimidex, Aromasin, and Letrozole to inhibit the aromatase enzyme and make it unable to aromatize any Testosterone into Estrogen.
Because Testosterone has Androgenic effects, it can cause many side-effects that come from activating the Androgen receptor. These effects include acne, hair loss, enlargement of the prostate gland, body hair growth and masculinizing effects if used in women (it is highly ill-advised for women to use this hormone).
Testosterone Propionate has the affinity to shut down production of endogenous Testosterone within the body. Therefore it is advisable to make use of Post Cycle Therap (PCT) utilizing drugs such as HCG, Proviron, Clomid and Nolvadex to boost natural production and return the body to homeostasis.
For the management of Low Testosterone, Testosterone Propionate is typically injected three times weekly. 25-50mg three times weekly should provide those with low Testosterone levels with a healthy replacement dose and for more advanced athletes dosages of 50-200mg every day or 3 times a week is not uncommon. Most people using Testosterone replacement will usually employ a longer lasting ester such as Enanthate or Cypionate. These longer ester compounds require less injections (once or twice weekly or bi-weekly) to ensure steady hormone levels.
Every milligram of Testosterone Propionate used results in more actual Testosterone being utilized by the body compared to a longer ester such as Testosterone Enanthate. It isreported that 100mg of Testosterone Propionate is about 125% stronger than 100mg of Testosterone Enanthate.