This is a good read..
Trenbolone enanthate was the steroid produced by underground labs to take the place of Parabolan, and its obscure ester. Tren enanthate basically is the longest acting version of tren we have available on the market right now, and it actually offers a couple of advantages over the traditional Tren A that's been available for the last couple of years as either an UG Product, or from converting Finaplex Pellets into an injectable.
I had the opportunity to be one of the first athletes in the world to try this product, from the UG "Stark Labs." It was so new, in fact, that when I sent it away for testing, the lab told me that they had nothing to really compare it to, and that they were simply estimating potency and legitimacy based on the respective values for the Trenbolone molecule and the Enanthate ester.
I'm not going to go into the various merits of trenbolone, but I would like to discuss some unique properties the Enanthate version has. For one reason or another, this stuff doesn’t give me tren cough, and I am particularly susceptible to this side-effect of Tren, which basically cripples me for the first week I use it. Regardless of whether I use home-brewed Tren, UG lab Tren, or Vet-Grade, I was basically crippled for the first week of use. I can't tell you why, exactly, this was, and can only speculate that it was due to a rise in prostaglandins. Tren enanthate didn't have this effect on me, however. Yeah, that's right. I know that the ester attached to a steroid doesn't dictate any of its properties, but in this particular case, I believe that the enanthate ester provided less of a sharp rise in prostaglandin levels and allowed my body to not develop the dreaded "tren-cough" that usually side-lines me when I start a cycle including Tren.
There is a method of prostaglandin production whereby prostaglandins made from one pathway in particular happen to dictate some muscle constriction as well as platlet aggregation, while the other method of production dictates bronchial constriction, and this could possibly be the means by which Tren Acetate causes that vicious cough. The reason why—though this is speculation—the enanthate version doesn't cause this rapid rise in prostaglandins is because of its more steady release, and my body's ability to gradually acclimatize itself to this. If you look at the graphs in the Minto studies (in the Deca profile), you'll see that the rise and rapid peak in blood plasma levels afforded by short esters are profoundly higher than those provided with longer esters, and it's my belief that the enanthate ester provides a lower peak level and less rapid rise in prostaglandin levels, especially the ones which dictate that second form of prostaglandin release which causes bronchial constriction. I feel that this bronchial constriction never really leaves you while you use any form of Tren, and this is what causes the shortness of breath experienced by many athletes on Tren.
Anyway, clearly the long estered Tren is a viable compound for those who wish to make minimal injections, and still use a nice lean-mass providing, non-aromatizing anabolic.