Tryptophan affects brain serotonin synthesis when given orally in a purified form and is used to modify serotonin levels for research. Low brain serotonin level is induced by administration of tryptophan-poor protein in a technique called acute tryptophan depletion.
Since tryptophan is an amino acid found in many foods, it is assumed to be safe in normal quantities. It's estimated that a typical diet contains 1 gram per day, but some individuals choose to supplement with doses of up to 5 grams per day
Naturally occurring tryptophan helps produce serotonin, which has several health benefits including helping to promote better sleep, providing relief from anxiety and depression, providing increased emotional well-being and also helping to manage pain tolerance.
Tryptophan plays a role in the production of serotonin, a mood stabilizer, melatonin, which helps regulate sleep patterns, niacin or vitamin B-3, and nicotinamide also known as vitamin B-3.