Faster digesting protein is desirable immediately before and after exercise to help refuel recovering muscles, but slow digestion and absorption may be more beneficial at other times including bedtime when your body typically goes for hours without food. Casein products are acid sensitive and thicken in the stomach. Compared to some other proteins, it can take longer for our GOLD STANDARD 100% Casein to be broken down into its amino acid subcomponents. By using only premium micellar casein as a protein source, we've created a formula that sets the standard for slow digesting protein support.