Metabolic Maintenance L-Tryptophan 500mg supports balanced mood, immune function, appetite regulation, and helps promote healthy sleep onset, duration, and quality. L-Tryptophan is the essential amino acid that acts as a precursor to 5-HTP, serotonin, melatonin, and niacin. Tryptophan assists with normal sleep patterns, mood, and appetite. Use with care when combining substances that increase serotonin levels. Recommended Use: Take 1 to 2 capsules daily on an empty stomach at bed time, or as directed by a healthcare professional.