I would not use it on cycle, nor off-cycle, since its benefits can not outweigh its disadvantages, especially when you have more effective and safer alternatives. First of all, the results are not long lasting with clenbuterol, and it WILL cause muscle wasting. It will do so because it increases your metabolism, and also because it will raise the levels of cortisol, which is very catabolic. Besides, it can cause insomnia, jitters, headaches, increased BP, stomach pain, cramps....and the list goes on. Why not use SARMS? They do not have side effects, they are anti-catabolic, and they are quite effective for fat loss.