L-Tryptophan

L-tryptophan is an amino acid, a protein building block that can be found in many plant and animal proteins. L-tryptophan is called an “essential” amino acid because the body can't make it. It must be acquired from food. L-tryptophan is important to the functions of many organs in the body. It can be converted into several important molecules, including serotonin and melatonin. Serotonin transmits signals between your nerve cells and also narrows (constricts) blood vessels. The amount of serotonin in the brain can affect mood. In the brain specifically, it influences sleep, cognition and mood. Meanwhile, melatonin is a hormone that’s most notably involved in your sleep-wake cycle