Tibolone, also known as 7α-methylnoretynodrel, as well as 7α-methyl-17α-ethynyl-19-nor-δ 5(10) -testosterone or as 7α-methyl-17α-ethynylestr-5(10)-en-17β-ol-3-one, is a synthetic estrane steroid and a derivative of testosterone and 19-nortestosterone .   It is more specifically a derivative of norethisterone (17α-ethynyl-19-nortestosterone) and is a member of the estrane subgroup of the 19-nortestosterone family of progestins.     Tibolone is the 7α-methyl derivative of the progestin noretynodrel (17α-ethynyl-δ 5(10) -19-nortestosterone).  Other steroids related to tibolone include the progestin norgesterone (17α-vinyl-δ 5(10) -19-nortestosterone) and the anabolic steroids trestolone (7α-methyl-19-nortestosterone) and mibolerone (7α,17α-dimethyl-19-nortestosterone). 
As alluded to above, one very important thing to acknowledge when using AAS (whether taking one hormone, stacking or cycling) is the risk of harmful side effects. Within a steroid cycle, the users will often stack other non-anabolic hormones into their program to maximize specific cycle objectives for example: the addition of drugs like Clenbuterol and/or Cytomel /T3 augment cutting/definition cycles; others called aromatase inhibitors (estrogen reducing drugs) like Letrozole . Letro and Anastrozole Arimidex are often included to inhibit the conversion of excess testosterone to negatively cycle impacting estrogen and; incorporating post-cycle therapy (PCT) drugs such as the synthetic estrogens Tamoxifen . Nolvadex , or Clomiphene Citrate . Clomid (which act as anti-estrogens in the male body), can be used alone, together, or in conjunction with those like Mesterolone . Proviron and Human Chorionic Gonadotropin ( HCG ) during PCT to bridge the gap between the end of a steroid cycle (synthetic testosterone usage) and the restoration of the bodys natural testosterone production. These drugs too must be researched, and controlled in similar fashion to AAS. Thus, steroid cycles can be as simple or complex as the users individualized goals, cycle histories and levels of understanding. Below are three samples of AAS stacked cycles of varying complexity along with a beginning PCT sample, and an explanation of goal intention & rationale for the selected compounds, dosages & durations. These illustrations and commentaries will provide a better understanding of what stacking and cycling are along with the many nuances they require.
* Testosterone-Propionate is optimal but Testosterone-Cypionate or Testosterone-Enanthate can be used if the Propionate is a problem for you.
* Trenbolone-Acetate will really set this cycle off more so than any steroid in the stack. If you respond poorly to the hormone you might replace it with Masteron-Propionate at a dosing of 300mg per week; three injections of 100mg each.
* While Equipoise on its own is not a great mass builder, coupled with Testosterone-Propionate and the initial Dianabol use you will produce some very solid gains and see your strength increase very nicely. Further, EQ will promote a more conditioned look while you’re still growing.
* Arimidex may not be needed for some but most will be best served with this low dose. If aromatase related side-effects become a problem you will need to increase the dose to 1mg/eod and in most all men this will eliminate the problems.
* How much weight can you gain from this cycle? That’s a hard question to answer; it will greatly depend on how high your calorie intake is. If you are eating a maintenance level diet you may be able to put on 7-10lbs of tissue, this is excluding any water weight that might come with the Dianabol but any water weight will dissipate shortly after it’s discontinued. Further, the Arimidex will greatly help control this issue. Moreover, the higher your carb intake is above necessity the more water you’ll probably hold.