L-Tryptophan is an essential amino acid that the body cannot produce on its own, meaning it must be obtained through diet. It is found in various protein-rich foods such as turkey, chicken, fish, dairy products, nuts, and seeds. L-Tryptophan plays a crucial role in the production of serotonin, a neurotransmitter that helps regulate mood, sleep, and appetite. In addition to its role in serotonin production, L-Tryptophan is also a precursor to melatonin, a hormone that regulates sleep-wake cycles. Due to its effects on mood and sleep, L-Tryptophan is sometimes used as a dietary supplement to help with conditions like insomnia and depression. However, it is important to consult a healthcare professional before starting any supplementation.