Herbalife is a brand of food supplements that has been around for a while and have proven to be reliable as such. Herbalife, and any other products in this one uses for a cleanse, whether it be 21 days, 14 days, or 7 days, must be considered in light of one's overall state of health. If one is a diabetic, is hypertensive or suffer from other chronic medical condition, one must use care to be certain that one does not suffer adverse reactions or complications due to unexpected outcomes of a treatment (a cleanse technique is a "treatment" in the sense that it will affect your overall body systems). A cleanse, in a sense, "stresses" one's body's systems in ways that non-physician may not be able to understand. Getting into the details of what happens to a person's body systems on the cellular or molecular level goes far beyond the scope of this online platform and I am not quite prepared to write a hub on this topic, just now (I don't have time, right now to write a hub, actually). Think about the 21 day cleanse, read up on it, and do not go into it "with your eyes closed," so to speak. This is all that I am saying.