Trenbolone Acetate has a double bond at carbons 9 and 11, which significantly raises its binding affinity to the androgen receptor, slows down its rate of metabolism and inhibits it from aromatizing. The result of these characteristics is that it is considered one of the most powerful anabolic steroids around. In addition to its hormone structure, Trenbolone Acetate also has the benefit of having a relatively small ester attached to it. This ester is attached in order to regulate the release time of the hormone after its injection. This controlled release gives Trenbolone Acetate an extended half-life of two days. However, Trenbolone Acetate could have a range of forty eight to almost seventy two hours. This means Trenbolone Acetate is a fairly fast acting steroid, and it also means that injections should happen somewhat frequently so as to stabilize blood levels. While Trenbolone Acetate carries with it some of the common characteristics of other steroids, there is one single characteristic that lifts it far above the pack, making it superior in terms of potency and power. Trenbolone Acetate enhances protein synthesis, which is essentially the building block of muscle growth.
The other category 2 of Trenbolone side effects can also be managed by closely monitoring the dose of the steroid that gets into the blood though this is not usually the case. Some users of this steroid can suffer from brutal anxiety attacks. Insomnia can last for several days. The worst is the increased heart rate. The user can experience a rapid heart rate which can be scary and can even lead to death. Unfortunately for the users, nothing much can be done to avoid these side effects. It’s either the body tolerates the steroid or it doesn’t, and if it doesn’t, you should never use it again.
Tibolone has tissue -selective estrogenic effects, with desirable effects in bone , the brain , and the vagina , and lack of undesirable action in the endometrium and breasts .  Its tissue selectivity is the result of metabolism , enzyme modulation (., of estrogen sulfatase and estrogen sulfotransferase ), and receptor modulation that vary in different target tissues, and differs mechanistically from that of selective estrogen receptor modulators (SERMs) such as tamoxifen , which produce their tissue selectivity via means of modulation of the ER.   As such, to distinguish it from SERMs, tibolone has been described as a "selective tissue estrogenic activity regulator" (STEAR),  and also as a "selective estrogen enzyme modulator" (SEEM).