L-Tryptophan 500 mg®

Amino Acids & Protein

Brand: NOW

CapsuleAmino acid/ProteinOn Market
Click to view full label

Net Contents

60 Veg Capsule(s)

Serving Size

1–2 Veg Capsule(s)

Servings Per Container

30

Supplement Form

Capsule

Bar Code (UPC/SKU)

7 33739 00166 5

Product Version

CODE 0166B V5

Label Analysis

Objective insights generated automatically from the official DSLD label — a quick, factual read of how this product is formulated and disclosed.

1Active Ingredients

Single-ingredient formula listed in Supplement Facts.

100%Amount Transparency

Every active ingredient discloses a specific amount per serving.

6Dietary Attributes

Label states: Vegan, Vegetarian, Non-GMO, Gluten-Free, Halal, Kosher.

This analysis is generated algorithmically from label data for educational reference only. It is not a product endorsement, ranking, or medical advice.

Supplement Facts

Serving Size: 1–2 Veg Capsule(s) · 2–3 per day

IngredientAmount Per Serving
L-Tryptophan1000 mg

Not Present

Other Ingredients

HypromelloseRice FlourAscorbyl PalmitateStearic Acid

Target Groups

VeganVegetarianAdult (18 - 50 Years)KosherHalalGluten FreeDairy Free

Label Claims

NutrientAll OtherStructure/Function

Directions & Suggested Use

Suggested/Recommended/Usage/Directions

Suggested Usage: Take 1-2 capsules 2 to 3 times daily on an empty stomach, with final dose at bedtime, or as directed by your physician.

Warnings & Precautions

Precautions re: Allergies

Not manufactured with wheat, gluten, soy, milk, egg, fish, shellfish, tree nut or sesame ingredients. Produced in a GMP facility that processes other ingredients containing these allergens.

Precautions re: Children

Caution: For adults only. Keep out of reach of children.

Precautions re: Pregnant or Nursing or Prescription Medications

Consult physician if pregnant/nursing, taking medication (especially antidepressants such as SSRIs and MAOIs), or have a medical condition.

Precautions re: All Other

May cause drowsiness. Do not use with alcoholic beverages or while operating heavy machinery.

Storage

Storage

Store in a cool, dry place after opening.

Formulation

Formulation re: Other

Supports Relaxation Encourages Positive Mood Promotes Restful Sleep

Formulation re: Does NOT Contain

Non-GMO

Formulation re: Vegetarian/Vegan

Vegetarian/Vegan

Formulation re: Does NOT Contain

Not manufactured with wheat, gluten, soy, milk, egg, fish, shellfish, tree nut or sesame ingredients.

Formulation re: Other

Natural color variation may occur in this product.

Formula re: Type

Crescent H (Halal)

Formula re: Kosher

Triangle K (Kosher)

Formula re: Contains

L-Tryptophan is an essential amino acid; therefore, it is not synthesized by the body and must be obtained from the diet. L-Tryptophan is critical for the production of serotonin and melatonin, which help to support a positive mood, healthy sleep patterns, and proper immune system function.

Formulation re: Does NOT Contain

Every lot of NOW L-Tryptophan is tested to be free of Peak E and microbial contamination.

Formulation re: Other

Made and quality tested in the USA with globally sourced ingredients.

FDA Statements

FDA Statement of Identity

A Dietary Supplement

FDA Disclaimer Statement

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.

Other Label Statements

General Statements: All Other Content

Amino Acids Family owned since 1968.

Seals/Symbols

GMP Quality Assured Triangle K (Kosher) Crescent H (Halal)

Manufacturer & Distributor

Manufacturer

NOW Foods

395 S. Glen Ellyn Rd., Bloomingdale, IL, 60108, USA

Market Reference

$3.00 – $115.35· 40 listings
  • Now Foods L- Tryptophan 500mg 90 Veg Capsules

    Natures Food Markets4.8(21)
    $22.49
  • NOW Foods L- Tryptophan Relaxation Support Capsules

    Vitacost.com4.6(4100)
    $13.46
  • Now Foods L-Tryptophan 500 mg

    Walmart - DailyVita4.6(5600)
    $22.41
  • (2 pack) NOW Supplements, L-Tryptophan 500 mg, Encourages Positive Mood*, Supports Relaxation*, 60 Veg Capsules, Size: 4.35, Other

    Walmart - Fruitful Yield4.6(5600)
    $29.72
  • NOW Foods L- Tryptophan Double Strength 1000 mg 60 Tablets

    Target4.6(1400)
    $22.99
  • (2 pack) NOW Supplements, L-Tryptophan 500 mg, Encourages Positive Mood*, 120 Veg Capsules, Beige

    Walmart - Fruitful Yield4.6(5600)
    $45.32
  • Now L-Tryptophan 500mg 120 Vegetable Capsules

    Locatel Health & Wellness Online Store4.6(4100)
    $17.79
  • NOW L-Tryptophan 500 mg 60 Vegicaps

    vitadvice.com4.5(2)
    $23.52

Where to Buy Locally

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Research & Studies

  • Oral tryptophan activates duodenal aryl hydrocarbon receptor in healthy subjects: a crossover randomized controlled trial

    GH Rueda, N Causada-Calo… - American Journal …, 2024 - journals.physiology.org

    … ) intake while containing less than 500 mg of l-tryptophan per day. Subjects were provided … l-tryptophan supplementation, which is not surprising as this study was performed in healthy …

    202430 citations
  • The FDA Ban of L-tryptophan: politics, profits and prozac

    DW Manders - Social Policy, 1995 - go.gale.com

    … use of amino acid nutritional supplement L-Tryptophan a few days … serotonin drugs - now among them L-Tryptophan itself - … extensive research on the medical politics of L-Tryptophan. …

    199511 citations
  • l-Tryptophan

    BMD Knapp, MJ Cupp, TS Tracy - … Supplements: Toxicology and Clinical …, 2003 - Springer

    … supplements that were commercially available in the United States include Tryptophan PRN 350 mg capsules, L-tryptophan 500 mg … be of generally worse health than controls and …

    20035 citations
  • Effects and side effects associated with the non-nutritional use of tryptophan by humans

    JD Fernstrom - The Journal of nutrition, 2012 - academic.oup.com

    … syndrome,’’ which requires medical attention. The symptoms of … Trp has been studied for these actions for 5 decades now and … Effect of L-tryptophan on brain serotonin metabolism in …

    2012143 citations
  • Intraduodenal calcium enhances the effects of L-tryptophan to stimulate gut hormone secretion and suppress energy intake in healthy males: a randomized, crossover …

    J Anjom-Shoae, PCE Fitzgerald, M Horowitz… - The American journal of …, 2024 - Elsevier

    Background In humans, intraduodenal infusion of L-tryptophan (Trp) increases plasma concentrations of gastrointestinal hormones and stimulates pyloric pressures, both key …

    202411 citations
  • Supplementing healthy women with up to 5.0 g/d of L-tryptophan has no adverse effects

    C Hiratsuka, T Fukuwatari, M Sano, K Saito… - The Journal of …, 2013 - academic.oup.com

    … intake of the essential amino acid L-tryptophan (L-Trp) have … Indeed, pellagra remains a public health problem in many … the nutritional requirements for L-Trp (300 mg/d in adults) (12) …

    201379 citations

Data sourced from the U.S. National Institutes of Health, Office of Dietary Supplements Dietary Supplement Label Database (DSLD) · Label entered 2024-07-25. DSLD Label ID: 314454. This information is provided for educational reference only and is not medical advice. Always follow the product label and consult a doctor or pharmacist before use.