Testosterone is the primary male sex hormone. It is the responsible for producing mainly male-specific sexual traits. When synthesized, it is usually attached to an ester to delay its release into the body. Testosterone Propionate is the shortest commonly ester attached to the Testosterone hormone. This means it takes your body the least amount of time to rid itself of the ester and release the parent hormone into the body. Due to its short active life, testosterone propionate typically needs to be injected every other day at a minimum. Anecdotally, testosterone propionate causes the least side effects and the least bloating; these side effects usually subside very quickly when use is ceased.