Ingredient guide
Conjugated linoleic acid is a family of fatty acids found naturally in dairy and beef. Meta-analyses show small effects on body weight and fat, around 1 kg over months of use, but the higher-quality subgroup of trials shows weaker or no fat-loss effect.
Mixed evidenceConjugated linoleic acid is a family of fatty acids related to linoleic acid, the omega-6 fat in seed oils. The natural source is the gut bacteria of cows and sheep, so small amounts are found in dairy and grass-fed beef. Supplements provide a concentrated mix of two main forms, cis-9 and trans-10 CLA, at doses far higher than you would eat from food.
Animal studies in mice show dramatic fat-loss effects, which set off years of human research and marketing. In people, CLA seems to influence the enzymes that store and burn fat, but the effects are far smaller. It may also nudge inflammatory and insulin signalling, which is where some safety concerns come from.
A 2011 meta-analysis of long-term trials in overweight people found a small statistically significant weight reduction of about 0.7 kg compared with placebo. A 2023 update was a little more positive but the high-quality subgroup showed no clear fat-loss effect. A small but consistent rise in fat-free mass was reported across analyses.
We grade the overall evidence as mixed. CLA can produce a small body weight change in the short term but does not match the dramatic mouse data. Some research has raised concerns about CLA worsening insulin sensitivity and liver fat in some people with metabolic issues, which is worth taking seriously.
Most trials use 3 g to 6 g per day, split with meals, for at least 12 weeks. Keep expectations small. Because some research has flagged a possible negative effect on insulin sensitivity and liver fat, people with type 2 diabetes, fatty liver, or insulin resistance should involve a healthcare provider before regular use.
Trials commonly use 3 g to 6 g of CLA per day, usually split into 2 or 3 doses with meals, for at least 12 weeks. Take with food to limit stomach upset. Ask your healthcare provider before regular use if you have insulin resistance, fatty liver, or take blood-thinning medicine.
Only a little. Meta-analyses show an average reduction of about 0.7 to 1.1 kg over months. It does not match the dramatic effects seen in mice.
Roughly the same compounds, but in vastly different doses. Supplements deliver gram-level amounts that food does not match.
There are concerns. Long-term high-dose use has been linked in some research with worse insulin sensitivity and more liver fat in some people.
Meta-analyses show a small rise in fat-free mass, but the effect is too small to count on for serious muscle gain.
