Tryptophan is the essential amino acid that acts as a precursor to 5-HTP, serotonin and melatonin. It also follows other metabolic pathways, including one that produces niacin. Tryptophan may promote balanced moods. Use with care when combining with substances that address serotonin.*

Physician's Choice - The health care professional's choice for high-quality supplements since 1984. We base our products on the latest wellness research and clinical studies, and use third-party testing for all incoming, in-process, and finished product. Products you can trust, at an exceptional value. Notes For Positive Use - Use with care when combining with substances that address serotonin.* Best taken between meals or before bedtime.*. Purity, Quality, Potency - No fillers, binders, preservatives, artificial colors or flavors. Vegetarian capsules. No gluten, egg, peanuts, tree nuts, or magnesium stearate. Supplements arrive in BPA-Free, recycled amber bottles that protect from light contamination. Supports Balanced Moods - Tryptophan is the essential amino acid that acts as a precursor to 5-HTP, serotonin and melatonin. These neurotransmitters are associated with the mood, and may promote balanced moods in already healthy individuals. *.