ArticleInternational journal of tryptophan research : IJTR2009
L-Tryptophan: Basic Metabolic Functions, Behavioral Research and Therapeutic Indications.
Article in International journal of tryptophan research : IJTR, 2009. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 302 papers, 2 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
302 citing papers in PubMed, 2 syntheses or guidelines pooled it, 611 citations in OpenAlex.
- Tryptophan and Its Derived Metabolites as Biomarkers for Tuberculosis Disease: A Systematic ReviewIranian biomedical journal · 2024Pooled it
- A sum of its parts: A systematic review evaluating biopsychosocial and behavioral determinants of perinatal depression.PloS one · 2024Pooled it
- Ischemic preconditioning modulates the acute post-exercise inflammatory, angiogenic, and neurotrophic response in endurance runners.Scientific reports · 2026Trial
- Pre-Sleep Alpha-Lactalbumin Supplementation Does Not Improve the Habitual Sleep and Performance of Sportspeople with Sleep Difficulties.Nutrients · 2025Trial
- Association between whole-grain consumption, tryptophan metabolism and psychological distress: a secondary analysis of a randomised controlled trial.The British journal of nutrition · 2024Trial
- Effectiveness of a Saffron and Withania Supplement on Mood in Women With Mild-to-Moderate Anxiety During the COVID-19 Lockdown.Depression and anxiety · 2024Trial
- Assessing and refining a metabolite-based distress score for use in different populations within three US cohorts.medRxiv : the preprint server for health sciences · 2026Article
- Study of the Formation of Neuromodulatory Compounds in Fermented Products Based on Triticale, Naked Oat, and Amaranth Grains.Foods (Basel, Switzerland) · 2026Article
- Tryptophan Metabolism in Digestive and Extra-Digestive Diseases: Mechanisms, Clinical Implications, and Therapeutic Perspectives.Nutrients · 2026Review
- Dietary Tryptophan Allocation in Depression: Serotonin-Kynurenine Balance, Microbial Indole Pathways, and Inflammatory Phenotypes.Nutrients · 2026Review
- Extending Sleep Improves Sleep and Stress Measures With Limited Microbiome Shift.Journal of sleep research · 2026Article
- A Cross-Sectional Study on Immune-Inflammatory Responses: Exposure to Polycyclic Aromatic Hydrocarbons Alters Pteridine Metabolism and Activates the Kynurenine Pathway.Chemical research in toxicology · 2026Article
- Article
- The multifunctional role of threonine in aquatic animals: linking growth, protein synthesis, digestion, and amino acid crosstalk.Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology · 2026Review
- A novel low-protein diet feeding strategy with reduced amylose/amylopectin ratio: effects on growth performance, gut health, and behaviour in nursery pigs.Veterinary and animal science · 2026Article
- Integrated transcriptomic and metabolomic analysis reveals potential candidate genes and regulatory pathways associated with egg weight in geese.Poultry science · 2026Article
- Severe Hospitalization-Requiring Viral Infection With Influenza or COVID-19: Metabolic Pathway Analysis.Open forum infectious diseases · 2026Article
- Tryptophan Metabolism at the Crossroads of Immunity, Barrier Function, and the Microbiome in Atopic Dermatitis.Clinical reviews in allergy & immunology · 2026Review
- Biomarkers of oxidative damage as a tool to investigate frailty syndrome in older women.npj aging · 2026Article
- Dietary silver nanoparticle supplementation induces Alzheimer-like lesions through Bifidobacterium deficiency-dominated gut microbiota dysbiosis and neuroinflammation.NPJ science of food · 2026Article
242 more citing papers are in PubMed but not listed here.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
6 authors at 2 institutions in 1 country.
Funding
Abstract
An essential component of the human diet, L-tryptophan is critical in a number of metabolic functions and has been widely used in numerous research and clinical trials. This review provides a brief overview of the role of L-tryptophan in protein synthesis and a number of other metabolic functions. With emphasis on L-tryptophan's role in synthesis of brain serotonin, details are provided on the research uses of L-tryptophan, particularly L-tryptophan depletion, and on clinical trials that have been conducted using L-tryptophan supplementation. The ability to change the rates of serotonin synthesis in the brain by manipulating concentrations of serum tryptophan is the foundation of much research. As the sole precursor of serotonin, experimental research has shown that L-tryptophan's role in brain serotonin synthesis is an important factor involved in mood, behavior, and cognition. Furthermore, clinical trials have provided some initial evidence of L-tryptophan's efficacy for treatment of psychiatric disorders, particularly when used in combination with other therapeutic agents.
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.