What does Conjugated Linoleic Acid (CLA) do?

Fatty acid supplement with modest evidence for reducing body fat and preserving muscle mass.

Is Conjugated Linoleic Acid (CLA) safe?

Liver safety concerns: at least one trial specifically evaluated liver function in women taking CLA, suggesting this is a known area of concern worth monitoring

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Conjugated Linoleic Acid (CLA)

Also known as: CLA, cis-9,trans-11 CLA, trans-10,cis-12 CLA, c9t11 CLA, t10c12 CLA

Effective Dosage

3–3.2 g daily based on study doses

What the Science Says

CLA is a naturally occurring fatty acid found in meat and dairy that is sold as a supplement for body composition. Clinical trials using 3–3.2 g per day over 12 weeks show it can modestly reduce body fat percentage and trunk fat, and may help preserve muscle mass — particularly in the trunk region. It also appears to suppress a fat-production process in the body called de novo lipogenesis, which may partly explain its effects on body fat and blood lipid levels.

What It Doesn't Do

Won't cause significant weight loss on its own — studies show body weight and BMI don't drop meaningfully. Not a diabetes treatment — one study noted reductions in insulin resistance markers but explicitly stated it should not be used to control or prevent diabetes. Anti-cancer claims are based entirely on animal and lab studies, not human trials. No proven benefit for COVID-19 or hair loss in humans based on the available evidence.

Evidence-Based Benefits

CLA at 3.2 g/day for 12 weeks showed modest preservation of trunk muscle mass in Chinese adults with elevated body fat, particularly in men and those with BMI <25 (PMID: 32684362). The same intervention suppressed de novo lipogenesis (DNL) activity, reducing erythrocyte C16:1n7 and C18:1n9 fatty acids while increasing C18:3n3, with associated changes in triglycerides and LDL-C (PMID: 41169023). In a small pilot study (n=15), 6-month CLA supplementation enhanced anti-inflammatory profiles of circulating myeloid cells in multiple sclerosis patients on first-line therapy, with supporting mouse model data showing attenuation of intestinal barrier dysfunction (PMID: 33899089).

Weak Evidence

Effective at: 3.2 g/day based on clinical trial data (PMID: 32684362, 41169023)

Source: auto-research

Absorption & Bioavailability

Unknown from provided studies — no pharmacokinetic data reported. Erythrocyte fatty acid changes were observed after supplementation, suggesting absorption occurs, but formal bioavailability data was not assessed in the provided papers.

Red Flags to Watch For

Liver safety concerns: at least one trial specifically evaluated liver function in women taking CLA, suggesting this is a known area of concern worth monitoring
Results are inconsistent across populations — effects on fat mass and muscle appear stronger in men and in people with BMI under 25, meaning it may not work equally for everyone
High doses in animal studies (fish) caused oxidative stress, inflammation, and liver cell death — human dose-safety thresholds are not well established from the provided studies
Nebulized (inhaled) CLA for respiratory infections is experimental with no controlled trial data — do not use CLA this way without medical supervision
Over 1,000 supplement products contain CLA, meaning formulations vary widely and quality control is inconsistent

Research Sources

PubMed
NIH DSLD

This information is for educational purposes only and is not medical advice. Always consult a healthcare professional before starting any supplement regimen. Last updated: 2026-04-06