SiS Overnight Protein is made from high quality milk protein for a great taste and trusted source of protein. The product formulation provides a source of slowly digesting protein to provide a pool of amino acid to support lean muscle growth and maintenance as you sleep. Each serving contains 26-27g of protein per serving, depending on the flavour you choose. The milk protein contains the same ratio of fast and slow release proteins as found naturally in milk. Milk protein is over 80% casein, which is a slowly absorbed protein, and around 20% whey, which is rapidly absorbed. Whey protein stimulates the rate of muscle protein synthesis with its’ high leucine content. The formulation has low levels of carbohydrate and fat.