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Sante Active Sedona Labs Similasan Sopharma Source Naturals Sports Performance StarChem Terra Ceutics Thermolife International Tribest Trimedica Twin Labs UltimateNutrition UltraLab Universal Nutrition VirtuVites Wakunaga/Kyolic Waterwise World Nutrition DEPARTMENTS Amino Acids Anti-Aging Anti-Oxidants Baby Health Bath & Body Bodybuilding & Sports Bone & Joint Books & Literature Brain & Memory Bulk Powders Clearance Cholesterol Circulation & Heart Cold & Flu Detoxification Digestive & Body Cleansing Enzymes Energy Eye Health Green Supplements Herbs Immune System Juicing Laxatives/Fiber Men's Health New Products Nutritional Oils Pet Nutrition Senior Health Sexual Health Skin Care Sleep & Relaxation Sprouting Stress & Mood Super Fruits Vitamins & Minerals Weight Loss Water Purification Women's Health   Amino Acids: L-Tryptophan L-Tryptophan is a natural amino acid that is the precursor to serotonin and melatonin, which is a neurohormone that affects the body’s ability to sleep, relax and feel good. It plays a part in the synthesis of both melatonin and serotonin, hormones involved with mood and stress response. L-Tryptophan also supports immune functions because it is the body's precursor to the kynurenines that regulate immunity. If needed, L-tryptophan coverts to niacin in the body, which supports circulation, a healthy nervous system, the metabolism of food, and the production of hydrochloric acid for the digestive system. American Nutrition is the largest retailer of L-Tryptophan products on the Internet. Due to the large volumes that we sell we have the lowest prices and the freshest product in the USA. Try our NutraceuticsRX Signature™ brand 500mg 120 Caps @ $24.95 ea for exceptional quality and value. Best Selling Amino Acids: L-Tryptophan Supplements Amino Acids: L-Tryptophan Pages: NRx L-Tryptophan USP - 500mg 120 Caps $49.90 $24.95 Our Price NRx98 (BEST VALUE) TOP SELLER! Independently Tested For Purity! Peak E Free.   Click on Product image for more information and Quantity Price Discounts Quantity    NRx L-Tryptophan Bulk Powder - 100g $99.90 $49.95 Our Price NRx123 (BEST VALUE) TOP SELLER! Independently Tested For Purity! Peak E Free.   Click on Product image for more information and Quantity Price Discounts Quantity    Lidtke L-Tryptophan 500mg 120 Caps $69.95 $59.95 Our Price LidtkeTryptophan120 500 mg--Guaranteed World’s Purest L‑Tryptophan! Promotes sleep and relaxation, improves mood, and reduces cravings for carbohydrates by boosting Serotonin levels. All natural, and non-addictive. FDA Registered, Certified Kosher, and surpasses all international pharmaceutical standards. 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