My Pro JYM protein powder is made from the highest-quality sources of protein. That's why I list the precise amount of each type of protein that is in every scoop of Pro JYM. Research confirms that the best gains in lean muscle mass are achieved with a protein blend that includes a fast-digesting protein (whey protein), a moderate-digesting protein (egg protein) and a slow-digesting protein (casein protein). These are the three protein sources that make up my Pro JYM protein blend. I optimized the amount of each one to maximize my own results as well as yours. - Jim Stopanni, PHD/ Owner - Jym Supplement Science