Isotonic means having the same fluid pressure as your other bodily fluids. Everything you eat or drink is processed in your stomach until it is at an isotonic state before it can pass into your small intestine into your bloodstream for nutrient absorption. Since Isotonix nutraceutical supplements enter your stomach already in the isotonic state and correct pH level, your body has to do very little work before it allows the solution to pass into the small intestine. Request your free sample packet of Isotonix Daily Essentials. This sample packet includes a single daily serving of: Isotonix OPC-3, Isotonix Multivitamin, Isotonix Activated B-Complex and Isotonix Calcium Plus in one convenient packet.