Optimal glutathione levels are important for everyone. Although you are hopefully in good health right now, glutathione levels fall as we age, and are lowered by a great number of very common illnesses. There is a constant demand for glutathione in our daily life; stress, pollution and infectious disease are all causes of glutathione depletion. For those that exercise regularly, glutathione is especially important to replenish to avoid injury, improve recovery time and keep your immune system strong.