Tryptophan (abbreviated as Trp or W) is one of the 20 standard amino acids. It is an essential amino acid in the human diet, meaning it must be obtained form food sources.
Tryptophan functions as a biochemical precursor for serotonin (which can then be converted to melatonin by enzymes in the body). Because of this tryptophan produces a calming effect or acts as a sleep-aid.
Tryptophan is a found in most protein-based foods or dietary proteins. It is particularly plentiful in chocolate, oats, bananas, mangoes, dried dates, milk, yogurt, cottage cheese, red meat, eggs, fish, poultry, sesame, chickpeas, sunflower seeds, pumpkin seeds, spirulina, and peanuts.