Glytactin BUILD 20 / 20 Oral Supplement Smooth Flavor Powder 33 ml Individual PacketOral Supplement Glytactin BUILD 20 20 Smooth Flavor Powder 1. 1 oz. Individual Packet Versatile powdered medical food for PKU available for those on a low phenylalanine diet who are seeking more protein, fewer calories and lower phenylalanine than other glycomacropeptide based PKU medical foods Glytactin Build 20 20 includes a complete profile of vitamins and minerals and is neutral in flavor so can be taken alone or as a way to build up the protein