CLA is a group of fatty acids from ruminant meat and dairy that gained popularity as a "fat burner." Our research shows the fat loss effect is real but very small — a meta-analysis of 18 RCTs found CLA produced only 0.05 kg/week additional fat loss vs placebo (about 1.1 lbs over 6 months). More concerning, CLA increases markers of insulin resistance, inflammation (CRP), and may promote fatty liver. The risk-benefit ratio does not favor supplementation for most people.
CLA works primarily through the t10,c12 isomer, which reduces lipoprotein lipase activity (less fat storage), increases carnitine palmitoyltransferase (more fat burning), and promotes adipocyte apoptosis (fat cell death). The problem is this same isomer also increases insulin resistance by promoting fatty acid flux to the liver and reducing adiponectin — an insulin-sensitizing hormone. So CLA burns a tiny amount of fat while simultaneously making your metabolism less healthy. In animals (especially mice), the fat loss is dramatic; in humans, it's disappointing.
No critical interactions identified.
Reviewed by the Scan Dose Research Team and Clinical Advisory Board | Last updated:
Not medical advice. Based on published clinical research and systematic reviews.