I personally like clen but I know its not good for the heart. The sides don't bother me at all except being a little bit shaky doing injections, and the shaking goes away pretty quick for me. Haven't tried an ECA stack because I haven't been able to find ephedrine. Haven't tried reta yet neither, but I likely will one of these days. Its weird to say, but I actually like the way clean makes me feel and I feel like i get a little bit stronger when I take it. Underground clen is like Russian roulette though because sometimes the dosing is all over the place