Deca Durabolin is a derivative of testosterone and is structurally similar to this androgen except that it lacks a 19th carbon. This drug also has weaker androgenic properties than testosterone, which might explain why its effects take a little time to become evident. Amidst this, Deca Durabolin is highly anabolic. Like most anabolic androgenic steroids, it stimulates protein synthesis and promotes muscle build up. It also provides the body with a positive nitrogen balance. It causes muscle to store more nitrogen than usual and this leads to more protein accumulation and therefore, more muscle growth and good gain muscle strength.

Other than those mentioned, the use of Deca Durabolin has many benefits. First, it stores more fluid in connective tissues, which helps in protecting joints from heavy loads and injury. Some athletes even report that it cures existing joint pains and gives room to pain-free workout sessions. Second, since Deca Durabolin is an injectable steroid, it can be used simultaneously with other steroids for more pronounced and well-maintained muscle bulk. An example is the famous combination of the oral Dianabol and injectable Deca Durabolin. The reason for such a use is that taking oral steroids alone produce fast effects but these gains usually become greatly reduced upon discontinuation of the drug. Adding an injectable steroid, which acts slowly but steadily, allows the effect started by the oral drug to be maintained even when you have stopped its use.

An advantage of Deca Durabolin over other steroids is that it has a low tendency for aromatization. While liver conversion of the drug to estrogen is still present, other sites of this process remain inactive. The effects of estrogen are less in this drug. Another advantage is that even if Deca Durabolin converts to an androgen, this androgen is much weaker than the highly potent dihydrotestosterone. This means that regular doses of the drug would rarely produce virilization in females, if it would produce any at all.