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). 
Tren- great medication, which gives excellent results on the path of "solo" to increase muscle mass without the need to be combined with other medications. However, it is a very powerful steroid, and therefore do not exceed the recommended dosage of certain: for acetate - is 50mg per day for enthatate: 300-350mg per week. To test the tolerance of Tren is better to start with a minimum dosage. If the entire rate is not more than six weeks, the need for additional formulations appears; when 6 to 8 weeks, with the need to enter the second week Gonadotropin (500 / 1000ME every 7 days) and stop taking it two weeks after administration cycle. Next, we have to be post-cycle therapy: start 14 days after the last injection or after 3days (if used Tren Acetate). To restore testosterone production take testosterone boosters (4 weeks after the course).