Depends on what you want to do for dosage, if you are running high dosage (100mcg or so) as a fat burner then 6 weeks should be good, if not you need to look at your diet and cardio...... If you are using it to aid in a bulking cycle and keep some fat off and increase protein synthesis, using a dose of 12.5-25mcg per day then I have heard that 12 weeks is fine. I am going to do that my next bulking cycle.

Pain