Safety Profile
Known Safety Concerns
- May stimulate thyroid hormone production -- contraindicated in hyperthyroidism
- Interacts with levodopa, thyroid medications, and MAOIs
- Blood pressure elevation at high doses
- Avoid if taking thyroid medication without medical guidance
Contraindications
- May stimulate thyroid hormone production -- contraindicated in hyperthyroidism
- Interacts with levodopa, thyroid medications, and MAOIs
Interactions
Information not yet available for this ingredient profile.
Evidence and Scientific Findings
Ingredient Overview
L-tyrosine is a precursor to dopamine, noradrenaline, adrenaline, and thyroid hormones. Used for cognitive performance under stress. May stimulate thyroid hormone production — contraindicated in hyperthyroidism. Interacts with thyroid medications, MAOIs, and levodopa. Blood pressure elevation possible at high doses.
Biological and Chemical Classification
- Scientific Name
- L-Tyrosine
Mechanism of Action
Information not yet available for this ingredient profile.
Clinical Evidence of Effectiveness
Information not yet available for this ingredient profile.
Pharmacokinetics
Information not yet available for this ingredient profile.
Recommended Dosage
Information not yet available for this ingredient profile.
SETI — Scientific Evidence Transparency Index
Executive Summary — Ingredient Assessment
- 10 studies reviewed
- 0 high-quality studies (meta-analysis or RCT)
- Main clinical benefit observed: Metabolic
- Evidence consistency: High consistency across studies (100%)
- May stimulate thyroid hormone production -- contraindicated in hyperthyroidism
- Interacts with levodopa, thyroid medications, and MAOIs
- Blood pressure elevation at high doses
- Avoid if taking thyroid medication without medical guidance
The available scientific evidence for L-Tyrosine indicates notable safety signals that warrant caution. Use should be considered carefully and monitored, particularly in sensitive populations or alongside other medications.
Total SETI Score
High risk| Evidence quality | 10/40 |
| Evidence consistency | 20/20 |
| Safety signals | 0/20 |
| Study recency | 10/10 |
| Evidence transparency | 10/10 |
Evidence Summary
- 10 studies reviewed
- 0 high-quality studies (meta-analysis or systematic review)
- 0 studies identified benefits or no safety concern (GREEN)
- 10 studies reported limited or advisory safety evidence (YELLOW)
Evidence Policy
Only peer-reviewed scientific literature indexed in PubMed or comparable databases is included in this evaluation. Commercial websites, blogs, and marketing materials are excluded. All references include direct traceable links to source documents.
Last updated: 15 აპრ 2026, 02:57
Evidence Distribution
-
Observational / other LOW evidence YELLOWSelf-Assembly and Crystal Structure of Boc-Protected Dipeptides Containing L-Phenylalanine and L-Tyrosine. ↗Baptista RMF et al.. Self-Assembly and Crystal Structure of Boc-Protected Dipeptides Containing L-Phenylalanine and L-Tyrosine.. Materials (Basel). 2026. PMID:41976605.PMID 41976605 ↗Journal Materials (Basel)Year 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41976605/
-
Observational / other LOW evidence YELLOWYeast u03b2-glucan alleviates alcohol-related brain injury by restoring gut-brain axis homeostasis. ↗Li H et al.. Yeast u03b2-glucan alleviates alcohol-related brain injury by restoring gut-brain axis homeostasis.. Int J Biol Macromol. 2026. PMID:41966379.PMID 41966379 ↗Journal Int J Biol MacromolYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41966379/
-
Observational / other LOW evidence YELLOWContinuous hypermutation and evolution of noncanonical amino acid synthases. ↗Furuhata Y et al.. Continuous hypermutation and evolution of noncanonical amino acid synthases.. bioRxiv. 2026. PMID:41959180.PMID 41959180 ↗Journal bioRxivYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41959180/
-
Observational / other LOW evidence YELLOWEnhancing Spatiotemporal Productivity of l-Tyrosine via Metabolic Flux Balancing and Population Engineering. ↗Dai Q et al.. Enhancing Spatiotemporal Productivity of l-Tyrosine via Metabolic Flux Balancing and Population Engineering.. ACS Synth Biol. 2026. PMID:41949909.PMID 41949909 ↗Journal ACS Synth BiolYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41949909/
-
Observational / other LOW evidence YELLOWEffect of supplemental feeding on metabolic profiles and meat quality in yaks: a non-targeted metabolomics approach. ↗Wang M et al.. Effect of supplemental feeding on metabolic profiles and meat quality in yaks: a non-targeted metabolomics approach.. Food Sci Anim Resour. 2026. PMID:41944906.PMID 41944906 ↗Journal Food Sci Anim ResourYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41944906/
-
Observational / other LOW evidence YELLOWAromatic amino acid metabolism shapes autophagy-mediated adaptation to iron deprivation in glioblastoma cells. ↗Zhao K et al.. Aromatic amino acid metabolism shapes autophagy-mediated adaptation to iron deprivation in glioblastoma cells.. Biometals. 2026. PMID:41925978.PMID 41925978 ↗Journal BiometalsYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41925978/
-
Observational / other LOW evidence YELLOWAcute high-temperature stress induces oxidative stress, ferroptosis, and metabolic homeostasis changes in the gills of Trachinotus ovatus. ↗Zhu R et al.. Acute high-temperature stress induces oxidative stress, ferroptosis, and metabolic homeostasis changes in the gills of Trachinotus ovatus.. Fish Shellfish Immunol. 2026. PMID:41921841.PMID 41921841 ↗Journal Fish Shellfish ImmunolYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41921841/
-
Observational / other LOW evidence YELLOWProtein Modifications and Metabolic Alterations in the Rat Striatum Following Oil Mist Particulate Matter Exposure Revealed via Untargeted Metabolomics and Phosphoproteomics. ↗Nie H et al.. Protein Modifications and Metabolic Alterations in the Rat Striatum Following Oil Mist Particulate Matter Exposure Revealed via Untargeted Metabolomics and Phosphoproteomics.. Toxics. 2026. PMID:41893517.PMID 41893517 ↗Journal ToxicsYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41893517/
-
Observational / other LOW evidence YELLOWPrognostic Value of O-(2-(18)F-Fluoroethyl)-l-Tyrosine PET for Patients with Recurrent Glioblastoma. ↗Geens W et al.. Prognostic Value of O-(2-(18)F-Fluoroethyl)-l-Tyrosine PET for Patients with Recurrent Glioblastoma.. J Nucl Med. 2026. PMID:41887733.PMID 41887733 ↗Journal J Nucl MedYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41887733/
-
Observational / other LOW evidence YELLOWCharting the path for L-tyrosine derivatives: from engineering strategies to microbial cell factories. ↗Zhou L et al.. Charting the path for L-tyrosine derivatives: from engineering strategies to microbial cell factories.. Nat Prod Rep. 2026. PMID:41873744.PMID 41873744 ↗Journal Nat Prod RepYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41873744/
Score Transparency
0 of 10 approved references (score saturates at 10). More peer-reviewed studies = stronger evidence base.
Method: Q = number of approved references ÷ 10 (capped at 1.0)
Limited — mostly case reports or animal studies
Method: L = mean study-level weight across approved references. Level 1 (meta-analysis / systematic review) = 1.0; Level 2 (RCT) = 0.8; Level 3 (cohort/case-control) = 0.6; Level 4 (case report) = 0.4; Level 5 (animal / in-vitro) = 0.2.
Mixed or neutral — roughly equal benefit and risk signals
Method: D = (sum of risk-scored references − sum of benefit-scored references) ÷ total evidence score, then scaled from [−1, 1] to [0, 1]. 0.0 = pure benefit; 0.5 = neutral; 1.0 = pure risk.
One or more monitoring-level safety signals active
Method: S = 0.5 (neutral baseline) + sum of active signal severity deltas ÷ 10. Severity deltas: Critical = +2.0, High = +1.5, Moderate = +1.0, Low = +0.5. Capped at 1.0.
Final GIRI Score for L-Tyrosine. Risk level thresholds: Low 0–3.0 · Moderate 3.0–5.5 · High 5.5–7.5 · Critical 7.5–10.
Full methodology & data sources
The GIRI Score is computed entirely from structured data — no editorial scoring or subjective weighting is applied at any step.
- References: Only approved references are counted. Each reference is assigned an evidence level (L1–L5) and a direction (risk / neutral / benefit) by the reference manager or AI classifier.
- Safety Signals: Sourced from regulatory agencies (FDA, EMA, Health Canada, TGA, and others) and pharmacovigilance databases. Only active signals count toward the score.
- Formula version: GIRI Score v3.7.0 — Q × L × D × S × 10.
- Limitations: The score reflects published evidence and recorded signals as of the last update date. It is not a clinical risk assessment and should not replace advice from a qualified healthcare professional.
Risk Level Classification
Based on available regulatory signals and scientific evidence, this ingredient presents a low safety concern under normal conditions of use.
0–3.0
3.0–5.5
5.5–7.5
7.5–10
The score pin shows exactly where this ingredient falls on the fixed risk scale.
What drove the Low classification for L-Tyrosine
A score of 3.5 places this ingredient in the Low band. Thresholds: Low 0–3.0 · Moderate 3.0–5.5 · High 5.5–7.5 · Critical 7.5–10.
0 approved references.
Limited — mostly case reports or animal studies (Level 4–5).
Neutral or mixed — benefit and risk signals roughly balanced.
No active signals — S component is at neutral baseline (0.5), contributing no extra risk weight.
No major regulatory restrictions or advisories recorded across monitored jurisdictions (FDA, EMA, Health Canada, TGA, and others).
How are the Low / Moderate / High / Critical thresholds defined?
The four risk levels are fixed score bands. A score is assigned to exactly one level based on where it falls:
| Level | Score | Meaning |
|---|---|---|
| LOW | 0.0 – 2.9 | Sparse or predominantly beneficial evidence. No active safety alerts. |
| MODERATE | 3.0 – 5.4 | Mixed signals — some risk alongside benefit. Caution at high doses or in sensitive groups. |
| HIGH | 5.5 – 7.4 | Multiple studies or regulatory alerts documenting adverse effects. Professional oversight recommended. |
| CRITICAL | 7.5 – 10 | Regulatory restrictions in one or more major jurisdictions. Serious documented harm. Avoid without specialist supervision. |
Thresholds are fixed constants (GIRI_Score_Utils::LEVEL_THRESHOLDS). They do not change per ingredient and are never subject to editorial adjustment.