Three Variants of Trenbolone
There are three variants of this powerful anabolic hormone: Acetate, Enanthate, and Hexahydrobenzylcarbonate. The only differences between these 3 variants are half-lives and release times. All 3 are identical in terms of the main compound, Trenbolone. The main issue between these variants becomes convenience and the timing of injections. For example, the short-estered Trenbolone Acetate has to be injected more frequently, which makes it less convenient. However, it also has a much shorter half-life—24-48 hours—which makes it easier for the user to stop use and clear his system in the event of harsh side effects. Whereas its Enanthate variant has a half-life of 7-10 days, and Trenbolone Hexahydrobenzylcarbonate has a half-life of about 2 weeks.
Gestodene, also known as 17α-ethynyl-18-methyl-19-nor-δ 15 -testosterone, as well as 17α-ethynyl-18-methylestra-4,15-dien-17β-ol-3-one or 13β-ethyl-18,19-dinor-17α-pregna-4,15-dien-20-yn-17β-ol-3-one, is a synthetic estrane steroid and a derivative of testosterone .   It is more specifically a derivative of norethisterone (17α-ethynyl-19-nortestosterone) and is a member of the gonane (18-methylestrane) subgroup of the 19-nortestosterone family of progestins.  Gestodene is almost identical to levonorgestrel in terms of chemical structure , differing only in having an additional double bond between the C15 and C16 positions, and for this reason is also known as δ 15 -norgestrel or as 15-dehydronorgestrel.  
Dienogest was synthesized in 1979 in Jena , Germany under the leadership of Kurt Ponsold, was initially referred to as STS-557 .   It was found that its potency was 10 times that of levonorgestrel .  The first product on the market to contain dienogest was a combined oral contraceptive pill (with ethinylestradiol), Valette, introduced in 1995 and made by Jenapharm .  In 2007, dienogest was introduced as Dinagest in Japan for the treatment of endometriosis, and it was subsequently marketed for this indication as Visanne in Europe and Australia in December 2009 and April 2010, respectively.  Qlaira was introduced in Europe in 2009 and Natazia was introduced in the United States in 2010.