Cinnamon's bark compounds modestly lower blood sugar and improve insulin response, most reliably in people with higher fasting glucose or prediabetes; effects on blood fats, blood pressure, and inflammation are smaller and less consistent. Benefits fade when stopped. True Ceylon cinnamon is far safer for daily use than common cassia. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Fasting blood glucose | 70–85 mg/dL | Tracks the primary glucose benefit |
| Hemoglobin A1c (HbA1c) | Below 5.3% | Reflects 3-month average blood sugar |
| Fasting insulin | Below 6 μIU/mL | Detects insulin resistance earlier than glucose |
| HOMA-IR | Below 1.5 | Direct index of insulin sensitivity |
| Lipid panel (triglycerides, LDL, HDL) | Triglycerides below 80 mg/dL; HDL above 50 mg/dL | Tracks the lipid effects of cinnamon |
| ALT and AST (liver enzymes) | ALT below 25 U/L (men) / 20 U/L (women) | Safety check for coumarin-related liver strain |
| hs-CRP | Below 1.0 mg/L | Tracks the anti-inflammatory signal |
| eGFR | Above 90 mL/min/1.73m² | Kidney-function context, relevant to at-risk metabolic users |
Cadence: Re-check glycemic and lipid markers at 8–12 weeks, then every 6–12 months if continued; check liver enzymes every 3–6 months with prolonged high-dose cassia use.