Nutrition Planet's 100% Micellar Casein contains milk-derived micellar caseins, the purest form of casein protein. A result of microfiltration, micellar casein is the most biologically intact form of casein protein and is untreated with heat or acid. As compared to calcium caseinate, Nutrition Planet's 100% Micellar Casein is a better acting protein source and prevents overnight and in-between meals, muscle breakdown. An outcome of cheese making process both casein and whey are milk-based proteins, but with different effects on muscle building process.