Chlorella consists of approximatively 60% protein in the form of amino acids. This is superior to other sources of protein from animals and vegetables which must be broken down to amino acids by the digestive enzymes in the stomach, and absorbed into the body through intestinal walls, before the body can utilize them for its own particular types of protein.
Among 22 different amico acids, all but 8 can be produced inside our body by using the other amino acids as material. These 8 amino acids can never be produced in our body, and must be consumed from food. These are called "essential amino acids". If any of these is even lacking, the others cannot function as well.
Chlorella contains 10 out of 22 different amino acids, and all 8 of the essential amino acids. Therefore, Chlorella is considered a complete protein.
Source: Chlorella The Ultimate Green Food by Beth M. Ley, Ph.D.
