CLA
Conjugated Linoleic Acid
Also known as: CLA, Linoleic Acid, Conjugated Linoleic Acid, Tonalin, Clarinol
Evidence Strength: MODERATE
This ingredient is classified as unclassified risk (GIRI score: 3.5/10). The classification is based on mechanistic and clinical evidence: cLA is thought to influence body composition by modulating lipid metabolism. It….
Safety Profile
Common Adverse Effects
- Nausea
- diarrhea
- stomach upset
- fatigue
- headache
Serious Adverse Effects
- Insulin resistance
- increased inflammation
- liver dysfunction
Contraindications
- Diabetes
- metabolic syndrome
- liver disease
- People taking Warfarin
Interactions
| Drug / Nutrient | Interaction Mechanism | Warning |
|---|---|---|
| Warfarin | increased bleeding risk — monitor INR closely. Antidiabetic drugs: potential for altered glucose control — adjust medication as needed. Statins: possible additive effects on lipid levels — monitor lipid profile. | Monitor |
Evidence and Scientific Findings
Ingredient Overview
Biological and Chemical Classification
- Chemical Class
- Fatty Acid
- Biological Class
- Lipid
- Natural Source
- Ruminant animals, dairy products
- Scientific Name
- Conjugated Linoleic Acid
- Chemical Formula
- C18H32O2
- CAS Number
- 2420-56-6
Mechanism of Action
Clinical Evidence of Effectiveness
| Indication | Evidence Level | Summary |
|---|---|---|
| General | Moderate | The clinical evidence for CLA's effectiveness in weight loss is mixed. Some studies suggest modest reductions in body fat and improvements in lean muscle mass, while others show minimal to no effect. The variability in results may be due to differences in study design, dosage, and duration. Overall, the evidence suggests that CLA may offer some benefits for body composition, but its impact on weight loss is not consistently significant. |
Pharmacokinetics
Recommended Dosage
| Condition / Use | Typical Dose |
|---|---|
| Weight management | 3-6 grams per day. Body composition improvement: 3-4 grams per day. |
Dosage ranges are based on clinical studies and commonly used supplement formulations. Individual requirements may vary.
SETI — Scientific Evidence Transparency Index
Executive Summary — Ingredient Assessment
- 10 studies reviewed
- 0 high-quality studies (meta-analysis or RCT)
- Main clinical benefit observed: Conjugated Linoleic Acid (CLA) is a type of polyunsaturated fatty acid found primarily in meat and dairy products.
- Evidence consistency: High consistency across studies (100%)
- CLA is generally considered safe for most adults when used at recommended dosages. However, individuals with diabetes or metabolic syndrome should exercise caution due to potential effects on insulin sensitivity. Pregnant and breastfeeding women should consult healthcare providers before use. There are no significant regulatory warnings associated with CLA.
- USA/FDA — Approved
The available scientific evidence for CLA 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: 06 მარ 2026, 12:01
Evidence Distribution
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Observational / other LOW evidence YELLOWThere may be a differential mechanistic impact on colorectal cancer of lactose-containing foods between lactase persistent and lactase non-persistent populations. ↗Szilagyi A et al.. There may be a differential mechanistic impact on colorectal cancer of lactose-containing foods between lactase persistent and lactase non-persistent populations.. Front Nutr. 2026. PMID:41756623.PMID 41756623 ↗Journal Front NutrYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41756623/
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Animal study LOW evidence YELLOWThe Effects of Supplemented Conjugated Linoleic Acid on Lipid Metabolism in Cattle. ↗Xiao C et al.. The Effects of Supplemented Conjugated Linoleic Acid on Lipid Metabolism in Cattle.. Animals (Basel). 2026. PMID:41751012.PMID 41751012 ↗Journal Animals (Basel)Year 2026Study type Animal studyEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41751012/
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Observational / other LOW evidence YELLOWThe Effect of Diet Acid Detergent Fiber Content on Finishing Lamb Meat Fatty Acid Composition, Tenderness and Stability. ↗Einkamerer OB et al.. The Effect of Diet Acid Detergent Fiber Content on Finishing Lamb Meat Fatty Acid Composition, Tenderness and Stability.. Food Sci Nutr. 2026. PMID:41704731.PMID 41704731 ↗Journal Food Sci NutrYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41704731/
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Observational / other LOW evidence YELLOWLipidomic Insight into Eggs and Meat of Quail (Coturnix japonica) as Potential 'Superfoods'. ↗Biau0142ek M et al.. Lipidomic Insight into Eggs and Meat of Quail (Coturnix japonica) as Potential 'Superfoods'.. Molecules. 2026. PMID:41683387.PMID 41683387 ↗Journal MoleculesYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41683387/
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Observational / other LOW evidence YELLOWc9, t11-Conjugated linoleic acid supplementation improves cognitive memory in u03c9-3 polyunsaturated fatty acid-deficient mice. ↗Ji W et al.. c9, t11-Conjugated linoleic acid supplementation improves cognitive memory in u03c9-3 polyunsaturated fatty acid-deficient mice.. Food Funct. 2026. PMID:41622908.PMID 41622908 ↗Journal Food FunctYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41622908/
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Observational / other LOW evidence YELLOWA Comprehensive Review on Medium- and Long-Chain Fatty Acid-Derived Metabolites: From Energy Sources to Metabolic Signals. ↗Park JB et al.. A Comprehensive Review on Medium- and Long-Chain Fatty Acid-Derived Metabolites: From Energy Sources to Metabolic Signals.. Metabolites. 2026. PMID:41590653.PMID 41590653 ↗Journal MetabolitesYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41590653/
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Animal study LOW evidence YELLOWFabrication and characterization of Idesia polycarpa-derived conjugated linoleic acid microcapsules by spray drying: In vitro digestion and release kinetics. ↗Yang H et al.. Fabrication and characterization of Idesia polycarpa-derived conjugated linoleic acid microcapsules by spray drying: In vitro digestion and release kinetics.. Food Chem X. 2026. PMID:41551806.PMID 41551806 ↗Journal Food Chem XYear 2026Study type Animal studyEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41551806/
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Observational / other LOW evidence YELLOWEffects of dietary supplementation of safflower seed oil (Carthamus tinctorius) on rainbow trout growth and physiological parameters (Oncorhynchus mykiss W.). ↗Bayir H. Effects of dietary supplementation of safflower seed oil (Carthamus tinctorius) on rainbow trout growth and physiological parameters (Oncorhynchus mykiss W.).. J Fish Biol. 2026. PMID:41539651.PMID 41539651 ↗Journal J Fish BiolYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41539651/
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Observational / other LOW evidence YELLOWGrazing versus housing in native dairy goats: Impacts on milk yield, composition, and conjugated linoleic acid enrichment under arid conditions. ↗Trejo-Lu00f3pez MT et al.. Grazing versus housing in native dairy goats: Impacts on milk yield, composition, and conjugated linoleic acid enrichment under arid conditions.. Vet World. 2025. PMID:41716174.PMID 41716174 ↗Journal Vet WorldYear 2025Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41716174/
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Observational / other LOW evidence YELLOWThe Safety of Nebulized Conjugated Linoleic Acid for COVID-19 Respiratory Tract Infections. ↗Jonsson ST et al.. The Safety of Nebulized Conjugated Linoleic Acid for COVID-19 Respiratory Tract Infections.. Cureus. 2025. PMID:41567914.PMID 41567914 ↗Journal CureusYear 2025Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41567914/
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 CLA. 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 CLA
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.
1 jurisdiction has active restrictions or advisories. Regulatory signals are recorded as Safety Signals and raise the S component.
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.