Tryptophan is an Essential Amino Acid that is the primary substrate from which the neurotransmitter Serotonin is produced. Serotonin is critical to feeling balanced, happy and grounded. Most people who feel stressed, depressed and/ or anxious have low Serotonin levels. Taking Tryptophan helps restore Serotonin levels. Tryptophan is also very useful for helping with poor sleep. Take Tryptophan on an empty stomach for maximal absorption. Our Tryptohpan Essentials is PURE Tryptophan without any additives.