I am currently running Spiropent brand Clen at 160mcg daily for one week on and then switching to one week ECA and then back to 160mcg Clen daily for another week. This is my first cycle of Clen ever and I can feel the effects although I obviiously have a natural tolerance to Clen because I dont have the shakes or anything hardcore like a lot of people get. I just feel warmer, sweat more and my resting heartrate is 115 in the morning before cardio and I can walk on the treadmill at 3.5mph to get my heart rate to a constant 140 beats per minute. Clen is alright, I dont see what the fuss is all about. I have noticed my waist line getting trimmer but then again my diet and cardio is like that of a Nazi. Very disciplined. Plus I am doing 50mg Winstrol ED to help retain strength and muscle.