The first time I tried clen, I didnt read up on the drug. So I used it for about a month. And I tapered up and down. With good results.
Recent cycles included clen, I have used it 2 weeks on 2 weeks off, so that the receptors dont get (my english sucks), "tired" of the drug.
I dont taper up. But when I run high dosages, I taper down.