Both the protein supplements are milk derivatives, an excellent source of essential amino acids. Given the physical characteristics of both the proteins (different rates of digestion), the protein supplement’s ability to stimulate muscle protein synthesis varies. Owing to its superior ability to increase the plasma concentration of amino acids to high levels within about 30 minutes of its consumption, Whey Protein is considered the most potent protein source to stimulate muscle protein synthesis. Micellar Casein forms micelles that can slow down digestion, hence taking several hours to digest and increasing amino acid levels. Fast-digesting protein is what you should look for after your workout, so consider taking Whey. The slow-digesting Micellar Casein is best when taken at bedtime, as it helps prevent muscle breakdown.