Conjugated Linoleic Acid (CLA)
A naturally occurring fatty acid found in dairy products and meat, taken in supplement form at much higher doses than found in food. Despite heavy marketing for fat loss, the evidence shows only very modest effects on body fat — and some studies suggest possible unfavourable metabolic effects.
Quick read · 3 min
A systematic review found a statistically significant but very small reduction in body fat of approximately 0.05 kg per week vs.
For context — weight loss from prescription medications:
How it works
CLA is proposed to reduce fat storage by altering fat cell metabolism and increasing fat burning. The exact mechanism is not fully established. In animal models, CLA shows clear anti-obesity effects — but human trials consistently show much smaller effects.
What the evidence shows
A systematic review found a statistically significant but very small reduction in body fat of approximately 0.05 kg per week vs. placebo. Over 6 months this equates to roughly 1.3 kg of fat mass reduction — very modest. Results are inconsistent across trials, and many studies have industry funding. The effect is on body fat specifically, not necessarily total body weight.
The trade-off
What this tends to offer:
- ✓Small but measurable fat loss in some trials
- ✓Available without prescription
- ✓Relatively affordable (~$20–$40/month)
What this involves:
- •Very small effect size (0.05 kg/week)
- •Potential negative metabolic effects (insulin sensitivity, inflammation)
- •Synthetic form differs from natural dietary CLA
- •GI side effects reported in some users
Safety
GI upset, nausea, and diarrhoea are common at higher doses. More concerning: some studies have found possible increases in insulin resistance and liver fat markers in people taking CLA supplements. These potential negative metabolic effects — particularly counterproductive in people with obesity — add caution to its use. Not recommended during pregnancy.
Written and maintained by one person · Built with agentic AI tools · Every number checked against the cited trial · Not medical advice
How this site is built →Last reviewed
In the Systematic review and meta-analysis (Onakpoya 2012), Statistically significant reduction in body fat of ~0.05 kg/week vs. placebo. Equates to ~1.3 kg over 6 months. Results inconsistent; industry funding prevalent. Some evidence of insulin resistance and liver fat increases.
Community insights
These are personal experiences shared in public online communities — not medical advice.
“The insulin resistance signal in some studies is a red flag — if you're taking CLA specifically for metabolic improvement, you may be counteracting yourself.”
“You'd need to eat huge amounts of grass-fed beef and dairy to get supplement-level CLA from food. Whether that's worth considering is another question.”
Common questions
After reading this page, most people compare this with other supplements, look at prescription options, or check what they can do today without a prescription.
Next step most people take
Built with agentic AI tools and not a substitute for medical advice
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