Micellar Casein is a milk protein and is well know for is slow digestion. Micellar Casein consists of approximately 80% protein, with minimal fats and carbohydrates. Micellar Casein can digest for up to 8 hours making it the perfect nigh-time protein for while you sleep. Since Micellar Casein is an 8 hour digesting protein it is best take before bed, or if you know you are going to go a long period of time without food and will require protein in your system.