GP Test U500 is an injectable preparation of the hormone testosterone. Testosterone is the most common anabolic hormone that there is and is also considered the most basic. Due to this, bodybuilders and athletes often consider it the base steroid to most all cycles. Testosterone is both anabolic and androgenic in nature. Users of this steroid will notice a dramatic gain in muscle size and strength, as well as an overall sense of well being and increases libido and sex drive. Testosterone aromatizes very easily and therefore estrogen buildup and side effects can become an issue for users sensitive to these problems or those choosing to use a high dose of this compound. Therefore, when using Testosterone, bodybuilders often choose in incorporate an anti-estrogen such as Anastrozole, Proviron, Tamoxifen to help keep estrogen related side effects to a minimum. Extremely sensitive users, or users using very high doses (800-1200mgs) might find that stronger anti-estrogens such as Letrozole or Exemestane are more suitable. Androgenic side effects such as oily skin are also possible while taking Testosterone. Those looking to bulk up, often add this drug with other steroids such as deca durabolin and/or equipoise, along with an oral compound such as dianobol or anadrol. Those looking to use testosterone during cutting phase might wish to stack it with compounds such as trenbolone or winstrol. Woman bodybuilders often use testosterone to build mass, although of course the dosage is significantly less than what males would use due to the possibility of masculizing side effects. The male user's dosage of this steroid would typically be in 400-1200mg per week range and cycle duration would be from 8-20 weeks, depending of course on the goals of the athlete. Women typically see desirable results from doses of 50-100mgs per week.