L-Tryptophan 500 mg®
Amino Acids & ProteinBrand: Protocol For Life Balance
Functions
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 07359 10166 1
Product Version
CODE P0166B V7
Label Analysis
Objective insights generated automatically from the official DSLD label — a quick, factual read of how this product is formulated and disclosed.
Single-ingredient formula listed in Supplement Facts.
Every active ingredient discloses a specific amount per serving.
Label states: Vegan, Vegetarian, Non-GMO, Gluten-Free.
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 per day
| Ingredient | Amount Per Serving | |
|---|---|---|
| L-Tryptophan | 1 Gram(s) | — |
Not Present
Other Ingredients
Target Groups
Label Claims
Directions & Suggested Use
Suggested/Recommended/Usage/Directions
Suggested Usage: Take 1-2 capsules twice daily on an empty stomach, with final dose at bedtime, or as directed by your healthcare practitioner.
Warnings & Precautions
Precautions re: Pregnant or Nursing or Prescription Medications
Cautions/Interactions: Tryptophan supplements may interact with CNS depressants, antidepressants (SSRIs, MAOIs), and other serotonergic agents such as St. John's Wort and 5-HTP. Consult your healthcare practitioner if you are taking medications or herbs, are pregnant/nursing, or if you have liver impairment.
Precautions re: All Other
May cause drowsiness. Do not use with alcoholic beverages or while operating heavy machinery.
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.
Storage
Storage
Store in a cool, dry place after opening.
Formulation
Formula re: Contains
How It Works: L-Tryptophan is an essential amino acid; therefore, it is not synthesized by the body and must be obtained from the diet. In the brain, Tryptophan is converted into serotonin, a neurotransmitter involved in feelings of well-being, calmness, personal security, and relaxation. It also plays a role in the regulation of appetite and synchronization of sleep patterns.
Formulation re: Does NOT Contain
Every lot of Protocol For Life Balance L-Tryptophan is tested to be free of Peak E and microbial contamination.
Formulation re: Other
Encourages positive mood Supports relaxation & 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.
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.
Manufacturer & Distributor
Manufacturer
Protocol For Life Balance
395 S. Glen Ellyn Rd., Bloomingdale, IL, 60108, USA
Market Reference
Protocol For Life Balance L-Tryptophan 500 mg
Vitacost.com4.7(143)$23.00L-Tryptophan 500 mg. (60 vegetarian capsules) ~ Protocol for Life
vitalgoods.com4.7(143)$24.20L-Tryptophan 500 mg
Natural Wellness Corner4.7(143)$23.00NOW Foods L- Tryptophan Relaxation Support Capsules
Swanson Health Products4.6(4100)$15.49Protocol for Life Balance Clinical Stress Relief 60 Capsules
Supplement First4.8(32)$33.00Protocol For Life Balance 5-HTP 100mg 90 Capsules
Vitacost.com4.8(83)$30.00Protocol For Life Balance 5-HTP 200 mg 60 Veg Capsules
Herbs Direct4.8(89)$32.00Protocol For Life Balance L-Carnitine 500 mg 60 Capsules
iHerb4.8(91)$27.00
Where to Buy Locally
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HEALTHHOME NUTRITION
4.9 (114)Sports nutrition store
C. de Gaztambide, 18, Chamberí, 28015 Madrid
NUTRIDEON
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Av. de Filipinas, 40, Chamberí, 28003 Madrid
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Pl. del Roble, 2, 28100 Alcobendas, Madrid
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Av del Santuario de Valverde, 11, 0, LOCAL, Fuencarral-El Pardo, 28049 Madrid
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C. del Dr. Esquerdo, 91, Retiro, 28007 Madrid
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C. del Corazón de María, 3, Chamartín, 28002 Madrid
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C.C. Parque Corredor, Carretera de Torrejón a Ajalvir, s/n, 28850 Torrejón de Ardoz, Madrid
GNC
3.3 (3)Vitamin & supplements store
28701 San Sebastián de los Reyes, Madrid
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
… with l-tryptophan supplementation, which is not surprising as this study was performed in healthy … l-Tryptophan supplementation did not affect cytokine production by PBMC with placebo, …
202430 citationsSerotonin, Kynurenine, and Indole Pathways of Tryptophan Metabolism in Humans in Health and Disease
M Holeček - Nutrients, 2026 - mdpi.com
… Many bacteria, including the genera Escherichia, Clostridium, and Bacteroides, hydrolyze TRP by tryptophanase (L-tryptophan indole-lyase) to indole, which exerts beneficial effects on …
202613 citationsL-Tryptophan: Basic Metabolic Functions, Behavioral Research and Therapeutic Indications
DM Richard, MA Dawes, CW Mathias… - International …, 2009 - journals.sagepub.com
… general healthy nutrition. While typical intake for many individuals is approximately 900 to 1000 mg daily, the recommended daily allowance for adults is estimated to be between 250 …
2009981 citationsA systematic review of the effect of L-tryptophan supplementation on mood and emotional functioning
AM Kikuchi, A Tanabe, Y Iwahori - Journal of dietary supplements, 2021 - Taylor & Francis
… This systematic review includes 11 RCTs that examined the effects of TRP intake on positive and negative mood in healthy adult populations. We have targeted healthy adult men and …
2021109 citationsSupplementing 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 citationsTryptophan As A Nutraceutical–Clinical And A Critical
MR Suchitra, P Krubaa, S Parthasarathy - European Journal of Molecular & … - academia.edu
… L Tryptophan is available in the commercial product as 125 mg/ capsule or 500 mg/ capsule … was lowered in preeclamptic compared with the healthy placental arteries, consistent with …
Data sourced from the U.S. National Institutes of Health, Office of Dietary Supplements Dietary Supplement Label Database (DSLD) · Label entered 2025-01-23. DSLD Label ID: 326453. 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.
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