Safety Profile
Known Safety Concerns
- TMAO production via gut bacteria -- cardiovascular disease association
- Fishy body odor (trimethylaminuria) at high doses
- Seizure threshold lowering reported in epilepsy patients
- Interaction with thyroid medications and warfarin
Contraindications
- TMAO production via gut bacteria -- cardiovascular disease association
- Fishy body odor (trimethylaminuria) at high doses
Interactions
Information not yet available for this ingredient profile.
Evidence and Scientific Findings
Ingredient Overview
L-carnitine is involved in fatty acid transport into mitochondria and is widely used in weight management and sports supplements. Gut bacteria convert carnitine to trimethylamine (TMA), which is oxidised to TMAO — a compound associated with atherosclerosis and cardiovascular disease. High-dose supplementation may therefore paradoxically increase cardiovascular risk. GI side effects include fishy body odor and nausea.
Biological and Chemical Classification
- Scientific Name
- L-Carnitine
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%)
- TMAO production via gut bacteria -- cardiovascular disease association
- Fishy body odor (trimethylaminuria) at high doses
- Seizure threshold lowering reported in epilepsy patients
- Interaction with thyroid medications and warfarin
The available scientific evidence for L-Carnitine 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: 24 მარ 2026, 09:04
Evidence Distribution
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Observational / other LOW evidence YELLOWLong-term effects of L-carnitine on hyperammonemia and hepatic encephalopathy in patients with liver cirrhosis: a multicenter retrospective study. ↗Tani J et al.. Long-term effects of L-carnitine on hyperammonemia and hepatic encephalopathy in patients with liver cirrhosis: a multicenter retrospective study.. Eur J Gastroenterol Hepatol. 2026. PMID:41870958.PMID 41870958 ↗Journal Eur J Gastroenterol HepatolYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41870958/
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Observational / other LOW evidence YELLOWL. carnitine modulates oxidative stress, steroidogenic gene disturbance, and testicular histopathology induced by Bisphenol A in male rats. ↗Emam NE et al.. L. carnitine modulates oxidative stress, steroidogenic gene disturbance, and testicular histopathology induced by Bisphenol A in male rats.. Vet Res Commun. 2026. PMID:41870818.PMID 41870818 ↗Journal Vet Res CommunYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41870818/
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Observational / other LOW evidence YELLOWBeyond Supportive Care: Mitochondria as a Strategic Therapeutic Avenue in Acute Pancreatitis. ↗Chooklin S et al.. Beyond Supportive Care: Mitochondria as a Strategic Therapeutic Avenue in Acute Pancreatitis.. Dig Dis Sci. 2026. PMID:41854947.PMID 41854947 ↗Journal Dig Dis SciYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41854947/
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Observational / other LOW evidence YELLOWA novel role for decadienyl-L-carnitine in pulmonary vascular remodeling and the underlying interventional mechanism of osthole. ↗Li Y et al.. A novel role for decadienyl-L-carnitine in pulmonary vascular remodeling and the underlying interventional mechanism of osthole.. Chin Med. 2026. PMID:41840734.PMID 41840734 ↗Journal Chin MedYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41840734/
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Observational / other LOW evidence YELLOWSspdhx Related to the Development and Virulence of Sclerotinia sclerotiorum Represents a Potential RNAi Target for Controlling Sclerotinia Disease. ↗Shang Q et al.. Sspdhx Related to the Development and Virulence of Sclerotinia sclerotiorum Represents a Potential RNAi Target for Controlling Sclerotinia Disease.. Mol Plant Pathol. 2026. PMID:41839654.PMID 41839654 ↗Journal Mol Plant PatholYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41839654/
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Observational / other LOW evidence YELLOWL-carnitine improves polycystic ovary syndrome by increasing CYP11A1, estrogen receptor, and decreasing XNIP and VEGF expression. ↗Lotfishokouh M et al.. L-carnitine improves polycystic ovary syndrome by increasing CYP11A1, estrogen receptor, and decreasing XNIP and VEGF expression.. Naunyn Schmiedebergs Arch Pharmacol. 2026. PMID:41838133.PMID 41838133 ↗Journal Naunyn Schmiedebergs Arch PharmacolYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41838133/
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Observational / other LOW evidence YELLOWEffects of Acetyl-l-Carnitine on the Mitophagy in the Spinal Cord Injury Progression Through PINK/Parkin Pathway. ↗Shen J et al.. Effects of Acetyl-l-Carnitine on the Mitophagy in the Spinal Cord Injury Progression Through PINK/Parkin Pathway.. J Biochem Mol Toxicol. 2026. PMID:41832947.PMID 41832947 ↗Journal J Biochem Mol ToxicolYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41832947/
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Observational / other LOW evidence YELLOWAcetyl-L-Carnitine in the Treatment of Peripheral Neuropathies: A Narrative Review. ↗Fornasari DMM. Acetyl-L-Carnitine in the Treatment of Peripheral Neuropathies: A Narrative Review.. Pain Ther. 2026. PMID:41824218.PMID 41824218 ↗Journal Pain TherYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41824218/
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Observational / other LOW evidence YELLOWMechanistic Insights into Perfluoroalkyl Substance-Induced Thyroid Hormone Disruption during Pregnancy: Evidence from Metabolomic Mediation Analysis. ↗Mo Z et al.. Mechanistic Insights into Perfluoroalkyl Substance-Induced Thyroid Hormone Disruption during Pregnancy: Evidence from Metabolomic Mediation Analysis.. Environ Sci Technol. 2026. PMID:41817240.PMID 41817240 ↗Journal Environ Sci TechnolYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41817240/
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Observational / other LOW evidence YELLOWChemometrics Assisted-Liquid Chromatography (LC)-Orbitrap High Resolution Mass Spectrometry (HRMS) Non-Targeted Metabolomics for Identification of Dog Meat in Beef Sausages. ↗Windarsih A et al.. Chemometrics Assisted-Liquid Chromatography (LC)-Orbitrap High Resolution Mass Spectrometry (HRMS) Non-Targeted Metabolomics for Identification of Dog Meat in Beef Sausages.. Food Sci Anim Resour. 2025. PMID:41822835.PMID 41822835 ↗Journal Food Sci Anim ResourYear 2025Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41822835/
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-Carnitine. 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-Carnitine
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.