Testosterone itself possesses a moderate level of Estrogenic activity, whereby it holds a moderate affinity to bind to the aromatase enzyme (the enzyme responsible for the conversion of Testosterone into Estrogen). Therefore, a moderate level of aromatization is to be expected with Testosterone use unless an aromatase inhibitor is utilized (such as Arimidex, Aromasin, and Letrozole) to inhibit the aromatase enzyme and therefore render it unable to aromatize any Testosterone into Estrogen. Therefore, Testosterone serves as a preferable compound for bulking but can also be utilized for cutting and fat loss phases as well. At the end of the day, however, Testosterone of any type is required in any cycle of any anabolic steroid if at least for the maintenance of proper physiological function of Testosterone in the body during a period in which the endogenous production of Testosterone has been suppressed or shut down from the use of anabolic steroids. Testosterone itself is also a very strong anabolic compound, suitable even on its own for any purpose, and is in fact suggested as the very first and only anabolic steroid that should be utilized in all first-time and beginner cycles.