CLA (conjugated linoleic acid)
What it is
Family of linoleic-acid isomers marketed for fat loss; proposed to reduce fat storage and increase fat oxidation.
What the evidence says
A 2007 meta-analysis (Whigham et al., American Journal of Clinical Nutrition) of placebo-controlled trials found CLA at about 3.2 g/day produced a small fat-mass loss of roughly 0.09 kg per week over up to six months — statistically significant but clinically minor, and the effect tends to plateau. Later reviews and the NIH Office of Dietary Supplements describe the evidence as weak and inconsistent, with little meaningful effect on body weight in humans. High doses have been linked to GI upset and, in some studies, reduced insulin sensitivity and adverse changes in blood lipids. Overall CLA offers at best a marginal fat-mass effect that does not translate into clinically useful weight loss.
Studies typically use about 3.2 g/day; higher intakes raise GI and metabolic side-effect concerns without added benefit.
Educational summary of doses studied — not a recommendation. Talk to a clinician before starting any supplement.
Sources (2)
- Efficacy of conjugated linoleic acid for reducing fat mass: a meta-analysis in humans — American Journal of Clinical Nutrition (2007)
- Dietary Supplements for Weight Loss — Health Professional Fact Sheet — NIH Office of Dietary Supplements (2024)
Educational summary of published research, checked against primary sources and linked inline. Not medical advice; supplements are not FDA-evaluated to treat disease. See our editorial policy.