Before you know the function of protein powder, you must first know what protein powder is and what its ingredients are, because the ingredients of a product determine its function. Protein powder is generally extracted from soybean protein and isoflavones, or is a powder composed of some casein and whey protein. Protein powder, as its name implies, is to supplement protein nutrition needed by human body. Of course, the functions of protein powder made of different raw materials will be different. Protein powder with soybean protein as the main component is suitable for ordinary people, because the molecular weight of soybean protein is relatively large and it will be more complicated to digest; Protein powder with whey protein as the main component is more suitable for the elderly, children and people who take protein supplements after illness, because whey protein has a small molecular weight and is easier to digest and absorb.