Max S Toro 250 ™ is a 19-nor derived steroid, in the 19-nor Testosterone (Nandrolone) family. In fact, Trenbolone is structurally similar to nandrolone, differing in the fact that it has a c-9 and c-11 double bond. The c9 bond serves to prevent any aromatization (conversion) to estrogen, and thus we see far less water retention with Trenbolone when we compare it to nandrolone decanoate. Unlike nandrolone however The c11 double bond also seems to increase Androgen Receptor binding quite profoundly (this may also have something to do with the c9 bond as well). This lack of estrogenic activity and powerful ability to bind to the androgen receptor combine to make Trenbolone a much more powerful androgen than nandrolone.