Safety Profile
Known Safety Concerns
- Very limited human safety data for isolated supplementation
- No established UL
- Rare: nausea at high doses
- Generally considered safe as dietary amino acid
Contraindications
- Very limited human safety data for isolated supplementation
- No established UL
Interactions
Information not yet available for this ingredient profile.
Evidence and Scientific Findings
Ingredient Overview
L-threonine is an essential amino acid involved in intestinal mucosal integrity, immune function, and collagen synthesis. Well tolerated at supplement doses. Very limited safety data specifically for supplemental L-threonine in humans. No established UL.
Biological and Chemical Classification
- Scientific Name
- L-Threonine
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%)
- Very limited human safety data for isolated supplementation
- No established UL
- Rare: nausea at high doses
- Generally considered safe as dietary amino acid
The available scientific evidence for L-Threonine 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: 25 მარ 2026, 12:49
Evidence Distribution
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Observational / other LOW evidence YELLOWSystems Metabolic Engineering of Escherichia coli for Efficient de novo Biosynthesis of 2,5-Dimethylpyrazine from Glucose. ↗Zhou X et al.. Systems Metabolic Engineering of Escherichia coli for Efficient de novo Biosynthesis of 2,5-Dimethylpyrazine from Glucose.. J Agric Food Chem. 2026. PMID:41823656.PMID 41823656 ↗Journal J Agric Food ChemYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41823656/
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Observational / other LOW evidence YELLOWEfficient production of glycine from glucose via a two-stage biosynthetic strategy. ↗Chen L et al.. Efficient production of glycine from glucose via a two-stage biosynthetic strategy.. Microb Cell Fact. 2026. PMID:41803809.PMID 41803809 ↗Journal Microb Cell FactYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41803809/
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Observational / other LOW evidence YELLOWEffect of solid-state fermentation on protein content, amino acid digestibility and anti-nutritional components of common beans, lentils and chickpeas. ↗Lux A et al.. Effect of solid-state fermentation on protein content, amino acid digestibility and anti-nutritional components of common beans, lentils and chickpeas.. Food Res Int. 2026. PMID:41794452.PMID 41794452 ↗Journal Food Res IntYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41794452/
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Observational / other LOW evidence YELLOWNon-excitatory Amino Acids Worsen Synaptic Transmission under Ischemia-like Conditions: Hypoxia and Hypoglycemia. ↗Ortega IG et al.. Non-excitatory Amino Acids Worsen Synaptic Transmission under Ischemia-like Conditions: Hypoxia and Hypoglycemia.. Curr Neuropharmacol. 2026. PMID:41755412.PMID 41755412 ↗Journal Curr NeuropharmacolYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41755412/
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Observational / other LOW evidence YELLOWDesign, synthesis and antibacterial activity of novel LpxC inhibitors containing 1,2,3-triazole moieties. ↗Jiang F et al.. Design, synthesis and antibacterial activity of novel LpxC inhibitors containing 1,2,3-triazole moieties.. Bioorg Med Chem Lett. 2026. PMID:41747910.PMID 41747910 ↗Journal Bioorg Med Chem LettYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41747910/
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Observational / other LOW evidence YELLOWToxicometabolomics Characterization of Two N1-Sulfonated Dimethyltryptamine Derivatives in Zebrafish Larvae and Human Liver S9 Fractions Using Liquid Chromatography-High-Resolution Mass Spectrometry. ↗Punnamraju P et al.. Toxicometabolomics Characterization of Two N1-Sulfonated Dimethyltryptamine Derivatives in Zebrafish Larvae and Human Liver S9 Fractions Using Liquid Chromatography-High-Resolution Mass Spectrometry.. Metabolites. 2026. PMID:41745615.PMID 41745615 ↗Journal MetabolitesYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41745615/
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Observational / other LOW evidence YELLOWPrecursor balancing by reprogramming pyruvate synthesis for high-yield l-isoleucine production in engineered Escherichia coli. ↗Huo X et al.. Precursor balancing by reprogramming pyruvate synthesis for high-yield l-isoleucine production in engineered Escherichia coli.. Bioresour Technol. 2026. PMID:41740936.PMID 41740936 ↗Journal Bioresour TechnolYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41740936/
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Observational / other LOW evidence YELLOWGenetic make-up and regulation of the L-lysine biosynthesis pathway in Vibrio natriegens. ↗Straube E et al.. Genetic make-up and regulation of the L-lysine biosynthesis pathway in Vibrio natriegens.. Microb Cell. 2026. PMID:41732680.PMID 41732680 ↗Journal Microb CellYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41732680/
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Observational / other LOW evidence YELLOWDiscovery of pyridomycin derivatives as InhA inhibitors from actinomycetes through molecular networking and an In-House tandem mass library. ↗Lee B et al.. Discovery of pyridomycin derivatives as InhA inhibitors from actinomycetes through molecular networking and an In-House tandem mass library.. Nat Prod Bioprospect. 2026. PMID:41622375.PMID 41622375 ↗Journal Nat Prod BioprospectYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41622375/
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Observational / other LOW evidence YELLOWMultiple Adenylate-Forming Enzymes Contribute to Biosynthesis of the DPO Quorum-Sensing Autoinducer. ↗Lacey DM et al.. Multiple Adenylate-Forming Enzymes Contribute to Biosynthesis of the DPO Quorum-Sensing Autoinducer.. ACS Chem Biol. 2026. PMID:41616077.PMID 41616077 ↗Journal ACS Chem BiolYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41616077/
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-Threonine. 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-Threonine
A score of 2.0 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.