Cellucor COR-Performance Casein is a gluten free delicious micellar casein protein from the makers of COR Performance Whey and C4. While fast digesting proteins such as whey are ideal to use around workout times, casein proteins are perfect for anyone wanting to boost their protein and amino acid intake whilst also supporting fullness and satiety. Its ability to digest slowly also makes it beneficial for long periods without nutrition and protein such as between meals and during sleep. As such, you will still be feeding your muscles with essential amino acids over many hours to help you recover and grow. COR Performance Casein is high in protein and low in carbs, sugar and fat making it a perfect supplement for those who want to stay lean and want to avoid any unnecessary fillers.