CLA
Research reviewed: Up until 03/2026
CLA (Conjugated Linoleic Acid) is a dietary supplement with 8 published peer-reviewed studies involving 2,340 participants, researched for Body Composition, Fat Loss, Immune Function and 1 more areas.
Evidence at a Glance
Strength is scored by study design, sample size, study type, and outcomes
Body Composition
StrongFat Loss
ModerateImmune Function
ModerateCardiovascular Health
ModerateResearch Visualised
Visual breakdown of the clinical data.
Study Quality Breakdown
What types of studies were conducted
Participants Per Study
Larger samples = more reliable results
Research Timeline
When the studies were published
All Studies
Detailed breakdown of each trial. Click to expand.
Body Composition
To evaluate CLA supplementation on body fat and lean mass in overweight adults.
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To evaluate CLA supplementation on body fat and lean mass in overweight adults.
Dose
3.2 g/day CLA mixture
Participants
157 overweight adults
Duration
6 months
Results
CLA supplementation significantly reduced body fat mass (-0.9 kg) and increased lean body mass (+1.1 kg) compared to placebo. Waist circumference was also reduced, confirming CLA's body recomposition effects.
How They Measured It
DXA body composition (fat mass, lean mass), waist circumference
To evaluate the effect of CLA on body fat in humans across multiple trials.
Study Type
Meta-analysis
Purpose
To evaluate the effect of CLA on body fat in humans across multiple trials.
Dose
3-6 g/day CLA
Participants
Pooled from 18 RCTs
Duration
6-12 months
Results
CLA supplementation produced a modest but significant reduction in body fat mass (pooled effect: -0.09 kg/week). The c9,t11 and t10,c12 isomers appear to have distinct mechanisms for fat reduction.
How They Measured It
Pooled fat mass changes across RCTs
To assess CLA supplementation during weight loss maintenance in obese adults.
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To assess CLA supplementation during weight loss maintenance in obese adults.
Dose
3.4 g/day CLA
Participants
134 obese adults in a weight loss maintenance programme
Duration
24 months
Results
CLA supplementation during weight maintenance significantly reduced regain of body fat mass compared to placebo. Lean mass was better preserved, suggesting CLA helps maintain body composition improvements.
How They Measured It
Body weight, body fat percentage, lean mass (DXA)
Fat Loss
To examine CLA supplementation on abdominal obesity and visceral fat.
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To examine CLA supplementation on abdominal obesity and visceral fat.
Dose
4 g/day CLA (t10,c12 isomer)
Participants
88 obese postmenopausal women
Duration
16 weeks
Results
CLA supplementation significantly reduced waist circumference and visceral fat area compared to placebo. The t10,c12 isomer specifically appeared to target abdominal fat depots.
How They Measured It
Waist-to-hip ratio, MRI visceral fat area, subcutaneous fat
To investigate the mechanism of CLA's anti-obesity effects in rodents.
Study Type
Animal study
Purpose
To investigate the mechanism of CLA's anti-obesity effects in rodents.
Dose
0.5% dietary CLA (t10,c12 isomer)
Participants
Obese Zucker rats
Duration
4 weeks
Results
CLA (t10,c12) significantly reduced adipose tissue weight and adipocyte size. PPARγ expression and lipogenesis were reduced, while fat oxidation markers increased, revealing the metabolic mechanism underlying CLA's fat-reducing effects.
How They Measured It
Adipose tissue weight, adipocyte size, lipid metabolism genes
Immune Function
To evaluate CLA supplementation on immune response to influenza vaccination in older adults.
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To evaluate CLA supplementation on immune response to influenza vaccination in older adults.
Dose
3 g/day CLA
Participants
73 older adults (aged 65-90)
Duration
12 weeks (including vaccination)
Results
CLA supplementation significantly enhanced the immune response to influenza vaccine, increasing antibody titres and NK cell activity compared to placebo. CLA may improve vaccine efficacy in the elderly.
How They Measured It
Antibody titres post-vaccination, T cell proliferation, NK cell activity
Cardiovascular Health
To assess CLA supplementation on blood pressure and cardiovascular risk markers.
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To assess CLA supplementation on blood pressure and cardiovascular risk markers.
Dose
3.2 g/day CLA
Participants
149 overweight adults with metabolic syndrome features
Duration
12 months
Results
CLA supplementation modestly but significantly reduced systolic blood pressure and LDL cholesterol. C-reactive protein was not significantly changed. Overall cardiovascular risk marker improvements were small.
How They Measured It
Systolic and diastolic blood pressure, lipid panel, CRP
To evaluate the cardiovascular effects of CLA supplementation in human trials.
Study Type
Systematic review
Purpose
To evaluate the cardiovascular effects of CLA supplementation in human trials.
Dose
Various (1.7-6 g/day)
Participants
Multiple RCT populations
Duration
Various
Results
CLA shows modest beneficial effects on lipid profiles in some studies. However, the t10,c12 isomer may negatively affect insulin sensitivity and should be used with caution in metabolic syndrome patients. Mixed isomer products appear safer.
How They Measured It
Review of RCTs on lipids, blood pressure, and atherosclerosis markers
Frequently Asked Questions
Common questions about CLA research
There are currently 11 peer-reviewed studies on CLA (Conjugated Linoleic Acid), involving 2,340 total participants. Research covers Body composition, Fat loss, Immune function and 1 more areas. The overall evidence strength is rated as Very Strong.
The evidence is currently rated as "Very Strong Evidence". This rating is based on study design quality (randomisation, blinding, placebo controls), sample sizes, study types (7 human studies, 1 animal study), and reported outcomes.
CLA has been researched for: Body composition, Fat loss, Immune function, Cardiovascular health. Each area has its own body of evidence which you can explore in the study breakdowns above.
Yes, 7 out of 11 studies are human trials. The remaining 1 is an animal study. Human trials carry more weight in our evidence scoring system.
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