L-Isoleucine
Also known as: Isoleucine, L-Isoleucine free form, Branched-chain amino acid
This ingredient is classified as unclassified risk (GIRI score: 1.5/10).
Safety Profile
Information not yet available for this ingredient profile.
Interactions
Information not yet available for this ingredient profile.
Evidence and Scientific Findings
Ingredient Overview
L-Isoleucine is an essential BCAA involved in muscle metabolism and immune function. It is safe at standard supplemental doses. Contraindicated in maple syrup urine disease. May mildly influence blood glucose at very high doses.
Biological and Chemical Classification
Information not yet available for this ingredient profile.
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: Amino Acids
- Evidence consistency: High consistency across studies (100%)
- No significant safety signals identified in the reviewed literature.
The available scientific evidence for L-Isoleucine 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: 26 მარ 2026, 14:19
Evidence Distribution
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Observational / other LOW evidence YELLOWSubstrate l-isoleucine facilitates the hyper inhibition of reveromycin A on human cytoplasmic isoleucyl-tRNA synthetase. ↗Chen B et al.. Substrate l-isoleucine facilitates the hyper inhibition of reveromycin A on human cytoplasmic isoleucyl-tRNA synthetase.. Arch Biochem Biophys. 2026. PMID:41839287.PMID 41839287 ↗Journal Arch Biochem BiophysYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41839287/
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Observational / other LOW evidence YELLOWIntegrating metabolomics and metagenomics reveals potential mechanism of rice root exudates in inhibiting nitrification in coastal saline soils. ↗Jiang J et al.. Integrating metabolomics and metagenomics reveals potential mechanism of rice root exudates in inhibiting nitrification in coastal saline soils.. Environ Res. 2026. PMID:41819201.PMID 41819201 ↗Journal Environ ResYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41819201/
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Observational / other LOW evidence YELLOWCo-Fermentation of Saccharomyces cerevisiae and Lactobacillus plantarum Enhances Mulberry Anthocyanin Stability via Amino Acid-Mediated Co-Pigmentation Mechanisms. ↗Yin X et al.. Co-Fermentation of Saccharomyces cerevisiae and Lactobacillus plantarum Enhances Mulberry Anthocyanin Stability via Amino Acid-Mediated Co-Pigmentation Mechanisms.. J Food Sci. 2026. PMID:41804074.PMID 41804074 ↗Journal J Food SciYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41804074/
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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 YELLOWUntargeted metabolomics reveals immune-metabolic signatures in established cases of rheumatoid arthritis. ↗Masood A et al.. Untargeted metabolomics reveals immune-metabolic signatures in established cases of rheumatoid arthritis.. Front Mol Biosci. 2026. PMID:41777668.PMID 41777668 ↗Journal Front Mol BiosciYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41777668/
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Observational / other LOW evidence YELLOWSafety and efficacy of a feed additive consisting of l-isoleucine produced with Corynebacterium glutamicumCCTCC M 2022764 for all animal species (Innobio Europe… ↗Villa RE et al.. Safety and efficacy of a feed additive consisting of l-isoleucine produced with Corynebacterium glutamicumCCTCC M 2022764 for all animal species (Innobio Europe B.V.).. EFSA J. 2026. PMID:41768353.PMID 41768353 ↗Journal EFSA JYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41768353/
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Observational / other LOW evidence YELLOWCrystal structures of two different 4-aminobutyrate aminotransferase-like racemases from the hyperthermophilic archaeon Pyrococcus horikoshii. ↗Kawakami R et al.. Crystal structures of two different 4-aminobutyrate aminotransferase-like racemases from the hyperthermophilic archaeon Pyrococcus horikoshii.. Int J Biol Macromol. 2026. PMID:41759851.PMID 41759851 ↗Journal Int J Biol MacromolYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41759851/
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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 YELLOWEnhanced Longevity and Immunity in Caenorhabditis elegans through Ingestion of Lactiplantibacillus plantarum SKO-001: A Multi-Omics Study. ↗Lee DJ et al.. Enhanced Longevity and Immunity in Caenorhabditis elegans through Ingestion of Lactiplantibacillus plantarum SKO-001: A Multi-Omics Study.. Food Sci Anim Resour. 2025. PMID:41821702.PMID 41821702 ↗Journal Food Sci Anim ResourYear 2025Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41821702/
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-Isoleucine. 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-Isoleucine
A score of 1.5 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.