Research synthesisModerate evidenceSmall effect6 studies · 5 beneficial · 1 neutral · 0 harmful
Across 6 studies, 5 reported beneficial effects of L-carnitine on triglyceride levels, with 4 meta-analyses showing small reductions and one RCT in PCOS women showing a large reduction. One systematic review in hemodialysis patients found no significant effect. The predominant effect size across beneficial studies is small. Doses around 2–3 g/day for approximately 6 weeks were commonly studied, primarily in populations with PCOS, impaired glucose tolerance, or diabetes.
- Effective dose range: 2000–3000 mg/day
- Studied populations: women with polycystic ovary syndrome (PCOS), adults with impaired glucose tolerance or diabetes, and hemodialysis patients
Caveats: The high proportion of beneficial findings (5 of 6) raises potential for publication bias, as null results are less likely to be published. Effects appeared neutral in hemodialysis patients in one large meta-analysis, suggesting benefit may not extend to all clinical populations. Most studies are meta-analyses with small effect sizes; the largest effect came from a single RCT in PCOS women and requires replication. Only one study reported duration (42 days), so the time course of effects is uncertain. Many studies did not specify the form of L-carnitine, but the only form reported was L-carnitine.
Generated Jul 12, 2026