Glutamine is one of the most important amino acids, which serves as a building block for protein. Glutamine makes up over 60% of amino acids in the body. Glutamine can increase muscle cell hydration and aid in protein synthesis. It is a nonessential amino acid, which means that the human body produces it naturally. Since it is produced naturally in the body, glutamine levels are depleted when you exercise. Therefore you should take a 5-10 mg of a glutamine supplement (pill or powder) right after you workout.