Depleting your body's natural amino acid supply can happen for a variety of reasons including exercise, aging, addictive behaviors, stress, medications, infections, vitamin deficiency, or a lack of varied protein. Common symptoms range from moodiness to fatigue.
An amino acid deficiency can lead to a wide variety of symptoms. Common symptoms that can be improved with supplementation include: moodiness, depression, anxiety, panic, fibromyalgia, chronic physical/emotional pain, recovery from addiction, soft tissue injury.
Taking a single amino acid can improve a single symptom but that one symptom stresses an entire system -- your body. Total repair of your body may require a "total" blend of all the amino acids to refuel your body's natural repair system.