Testosterone Cypionate is one of the many esterified variants of Testosterone available, and is most likely the second most popular esterified variant (the first being Testosterone Enanthate). It is an injectable form of Testosterone with a slow rate of release and a longer half-life. However, the release rates and half-life of both Testosterone Cypionate and Testosterone Enanthate are very much identical and the two compounds are easily interchangeable (for example, an individual can easily run a 10 week cycle of Testosterone and switch between Testosterone Enanthate and Testosterone Cypionate seamlessly). Testosterone Cypionate possesses a half-life of approximately 12 days while Testosterone Enanthate possesses a half-life of approximately 10 days – hardly much difference. The interesting fact about Testosterone Cypionate, however, is that it seems to have a distinct favor of popularity among American bodybuilders and athletes over the Enanthate variant. These distinctions are not extreme, however, and the commonality of use and availability of both variants is almost equal with Testosterone Enanthate ever so slightly more popular. Neither variant possesses any advantages over the other.