Does Clen have same effectiveness as first cycle?

I am about to start a cycle of clen today, and would like to know if clenbuterol has the same effectiveness as the first time you used it. I was told that it woks best the first time you use it and thier after each cycle it becomes less effective. Thank you for the help. :confused:

how much time are leaving between cycles? you have to give the receptor sites time to recover.