L-Tryptophan 500 mg®
Amino Acids & ProteinBrand: Protocol For Life Balance
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 P0166 V4
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, 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) · 2–3 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: As a dietary supplement, take 1-2 capsules 2 to 3 times 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 or tree nut ingredients. Produced in a GMP facility that processes other ingredients containing these allergens.
Precautions re: All Other
Do Not Eat Freshness Packet. Keep in Bottle.
Storage
Storage
Store in a cool, dry place after opening.
Formulation
Formulation re: Vegetarian/Vegan
Vegetarian/Vegan
Formulation re: Does NOT Contain
Not manufactured with wheat, gluten, soy, milk, egg, fish, shellfish or tree nut 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
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.*
Brand IP Statement(s) re: (c), (TM), (SM)
Every lot of Protocol For Life Balance(R) L-Tryptophan is tested to be free of Peak E and microbial contamination.
General Statements: All Other Content
Formulated by doctors and clinical scientists exclusively for licensed healthcare practitioners.
General Statements: All Other Content
• Premium Grade • Supports Relaxation* • Encourages Positive Mood* • Promotes Restful Sleep*
Seals/Symbols
GMP
General Statements: All Other Content
Please Recycle.
General: Product/Version Code
CODE P0166 V4
Manufacturer & Distributor
Manufacturer
Protocol For Life Balance(R)
395 S. Glen Ellyn Rd., Bloomingdale, IL, 60108, USA
Other
Market Reference
Protocol For Life Balance L-Tryptophan 500 mg
Vitacost.com4.7(96)$23.00
Protocol For Life - L-Tryptophan 500mg - 60 Capsules
Pure Prescriptions4.7(96)$23.00
PROTOCOL FOR LIFE L-Tryptophan 500 mg - 60 Veg Caps
Hasan Mirza, MD4.7(96)$23.00
L-Tryptophan 500 mg. (60 vegetarian capsules) ~ Protocol for Life
vitalgoods.com4.7(96)$24.20
L-Tryptophan 500 mg
Curated Wellness4.7(96)$23.00
Protocol For Life Balance L-Carnitine 500 mg 60 Capsules
iHerb4.8(88)$27.00
Natural Balance L- Tryptophan 500 mg 60 ct
Vitacost.com4.4(19)$29.69
Life Extension L- Tryptophan 500 mg 90 Capsules
Life Extension4.7(496)$24.75
Where to Buy Locally
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Aphro-D
4.6 (69)Vitamin & supplements store
548 Market St, San Francisco, CA 94104
The Vitamin Shoppe
4.5 (80)Vitamin & supplements store
115 Colma Blvd, Colma, CA 94014
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4.7 (18)Vitamin & supplements store
45-D Serramonte Center Spc D382, Daly City, CA 94015
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5.0 (1)Vitamin & supplements store
333 Bush St Ste 406, San Francisco, CA 94104
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5.0 (109)Vitamin & supplements store
115 E 4th Ave, San Mateo, CA 94401
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4.9 (16)Vitamin & supplements store
6309 Mission St, Daly City, CA 94014
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2.9 (18)Vitamin & supplements store
3251 20th Ave #155, San Francisco, CA 94132
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200 Westlake Center, Daly City, CA 94015
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, …
202428 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 …
20266 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 …
2009967 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 2013-07-25. DSLD Label ID: 23604. 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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