Research synthesisModerate evidenceModerate effect5 studies · 4 beneficial · 1 neutral · 0 harmful
Across 4 out of 5 studies, cinnamon demonstrated beneficial effects on reducing fasting blood glucose levels, with effect sizes ranging from moderate to large. The highest-quality evidence comes from a meta-analysis of 3,054 adults with type 2 diabetes, finding a significant moderate reduction (WMD: -15.26 mg/dL; 95% CI: -22.23 to -8.30). Effects were typically observed after 30–84 days of supplementation, with doses of ≤2 g/day (including 600 mg/day) commonly studied in clinical populations with type 2 diabetes.
- Effective dose range: 600 mg to 2 g per day
- Studied populations: adults and elderly with type 2 diabetes
Caveats: 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). The median study duration was 57 days, so shorter-term effects are less certain. Effect estimates showed high heterogeneity (I²=88%) in the largest meta-analysis, indicating variability in results across studies. Some trials combined cinnamon with other supplements (e.g., berberine), making it difficult to isolate cinnamon's independent effect. Dosing forms were not reported in the included studies.
Generated Jun 15, 2026