A Picture Of Health Pure Hydrolysed Collagen (Unflavoured) PowderA Picture Of Health Pure Hydrolysed Collagen (Unflavoured) 500G Source of protein and amino acids Pasture raised and grass fed. Collagen is a source of protein and amino acids. Collagen is found in high concentration in connective tissue, blood vessels and the intestinal wall. Collagen is found in many types of connective tissue, including skin, cartilage, ligaments, tendons and bones.