Dietary Supplement. Exercise Recovery*. Provides fuel for your workout*. Supports protein metabolism*. Supports recovery from workouts*. Post-Workout Met-Rx® L-Glutamine powder is an amino acid supplement often used by active men and women, bodybuilders and athletes, glutamine levels may decrease with intense training and glutamine levels in the body with the proper supplementation in order to effectively support your recovery after exercise.* Met-Rx® L-Glutamine powder may also provide you with fuel for your workout and help support protein metabolism by utilizing itself as cellular f.