Across all 3 studies, L-carnitine supplementation consistently shows beneficial effects on reducing HOMA-IR, with effect sizes ranging from small to moderate. The most studied population is adults, including those with overweight/obesity, and the evidence converges on doses of ≥2 g/day. Available evidence is overwhelmingly positive but the evidence base is small (only 3 studies) — conclusions should be considered preliminary.
Caveats: Evidence base is small (only 3 studies) — conclusions should be considered preliminary. Available evidence is overwhelmingly positive — clinical literature in this area is subject to publication bias (null-result studies are less likely to be published or indexed). Most studies were systematic reviews/meta-analyses that included diverse populations; individual-level dose durations and forms were not consistently reported in the extracted data.
significant effects of L-carnitine on ... HOMA-IR (MD = -0.58, 95% CI: -0.77 to -0.38)
L-carnitine emerged as the most effective and consistent intervention, producing significant reductions in body weight, body mass index (BMI), waist circumference, fasting blood glucose, Homeostatic Model Assessment for Insulin Resistance (HOMA-IR), and LDL-Cholesterol (LDL-C), along with a significant increase in HDL-Cholesterol (HDL-C).
L-carnitine supplementation had a significant effect on ... homeostasis model assessment-estimate insulin resistance (HOMA-IR) [WMD = -0.73; 95% CI, -1.21 to -0.25; p = 0.003]