An essential amino acid found in most proteins such as eggs, meat, fish, sesame seeds and Brazil nuts. Most fruits and vegetables contain very little Methionine. Methionine is required for normal growth and repair of body tissues. Methionine cannot be made by the body, and must be obtained from the diet: thus, it is considered an “essential” amino acid. There are two types of methionine—L-methionine (which is naturally-occurring) and D-methionine. Each contains the same chemical make-up, but the molecules are mirror images. A mixture of the two is called DL-methionine.