I never knew much about it. I only used what gear I was knowledgeable with, and Tren wasn't one of them. I had a co-worker peak my interest and I tried several different bottles for about 22 weeks straight! I liked it. I know That is a super long cycle but it didn't effect me very negatively. I will say it yields awesome results, but it will also be different from one brand to the next. I put on some good lean weight and got super dry, cut and vascular. I also suffered from horrible bouts of insomnia and irritation in the beginning of the cycle. At the end of the mega cycle I was just very lethargic all of the time, to the point I thought something was wrong with me. I switched brands and my sides switched also. I am currently off of it for the time being. But that is just my take on it. I'll def be back on it probably sooner than later. Right now I am just running the Test, Equipoise, Clen and GW501516. I am happy with this stack so far.