L-glutamine is a natural amino acid that is vital for muscle growth, maintaining a healthy digestive system and supporting brain function. L-glutamine is the most abundant amino acid in the body and is an important building block of protein. It has been categorised as a conditionally essential amino acid that is required in greater amounts during times of extreme stress, physical trauma, illness and muscle wasting. Glutamine Pure comes in a highly absorbable powder form and contains a whopping 5 grams of L-glutamine per teaspoon.