To be honest, I would always cycle off and on due to anything that is introduced into your body exogenously. If I could talk people into buying and using my stuff and never cycling off of any of it, I would if I had no conscience, but it would be no different than me telling people to keep using ephedra without ever coming off. Even with a diet, I would suggest a cheat meal a couple of times per week to just throw the body a curve. I would cycle off because it is an exogenous product that you are consuming. Each person would probably know how long they can stay on something until it loses it's effectiveness, and give a little bit of time to stay off before starting again. Even with the Carb Free, I wouldn't run it without giving it a break. The body always adapts. I honestly would use Carb Free only when you want to eat a bit more carbs than you would normally eat for your diet. That randomizes it's use.