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). 
Women respond well to a dosage of 50-100mg per week, although (as stated above) the oral should usually be given preference. Additionally, some choose to include Winstrol Depot or Oxandrolone and receive a greatly enhanced anabolic effect. Remember though, androgenic activity can be a concern and should be watched, particularly when more than one anabolic is used at a time. If stacking, it would be best to use a much lower starting dosage for each drug than if they were to be used alone. This is especially good advice if you are unfamiliar with the effect such a combination may have on you. A popular recommendation would also be to first experiment by stacking with oral Primobolan, and later venture into the injectable if this is still necessary.