Vanadyl sulfate was discovered to mimic the effects of insulin in human body. What it does is shuttle glucose molecules into the muscle cells and into the liver. There is evidence that this product will temporarilly increase muscle size by filling out the muscle cells with extra glucose. Vanadyl helps the body avoid undue protein breakdown as well. In laymans terms what this supplement does for you is give you an increase in endurance as well as a better pump in the gym. It also helps to give you better vascularity, especially in your arms.