i agree with everyone else, might as well run the clen straight through, use bendryl to upregulate receptors every 3rd week. there is some research on here that even shows clen may have some mild anabolic properties when run 6 weeks. however if u were dead set on the 2 wk on 2 off theory then the HH should be fine since it has no ephedra in it which also utilizes the beta receptors that clen uses.