Casein is another form of milk protein that takes longer to digest than whey, making it good as a night time protein. Calcium Caseinate is a synthetic extraction of casein from milk that is a “protein salt”. There isn’t as much information on caseinates as protein sources and they are generally not as well accepted as micellar casein (being a cheaper process) for bodybuilding. Caseins in general tend to clump together in the stomach which makes them digest much more slowly than whey making it more popular as a secondary protein source to provide longer term amino acid release. There is some debate as to whether calcium caseinate is a good absorbable protein, but it should be similar to other to other caseinates and should provide a slow digesting complete protein source.