That depends a lot on what your goals are. Typically, it is considered important for the sake of your health not to take the drug continuously. You will want some time away from the drug in order to give your body the time it needs to recover. This can be invaluable time for your liver to flush out toxins and return to a healthier state before you begin again. Consider a 10-week cycle of the drug. For the last two weeks, gradually reduce the dosage to help get your body off of it before stopping completely. This will help to reduce issues regarding side effects.