Ceylon Cinnamon

Blood sugarAnti-inflammatory

The 'true' cinnamon. Modest blood sugar effects; far safer than cassia cinnamon (the cheap supermarket kind), which contains liver-toxic coumarin.

EvidenceModerate

Modest evidence for HbA1c (~0.5% reduction), post-meal glucose smoothing, lipid improvements. Effects: 8–12 weeks.

There are two cinnamons. Ceylon cinnamon (Cinnamomum verum / zeylanicum) is the 'true' cinnamon, native to Sri Lanka — lighter colour, milder taste, very low coumarin. Cassia cinnamon (Cinnamomum cassia) is what's in most supermarket cinnamon, especially the cheaper kind — darker, stronger flavour, but high in coumarin (a liver-toxic compound at chronic high doses). For supplemental use, Ceylon is the right choice. Modest evidence for HbA1c reduction, post-meal glucose smoothing, and triglyceride improvement.

Form
Ceylon cinnamon (Cinnamomum verum) powder or extract. Check label — most supermarket cinnamon is cassia.
Dose
1–6 g/day (typically as 500–1,000 mg capsules or 1–2 tsp powder).
Timing
With food. AM is common.
Schedule
Daily.
Side effects
Generally well-tolerated. Mouth/lip irritation at high doses. Cassia cinnamon at chronic high doses can cause liver toxicity (coumarin) — Ceylon avoids this.
Interactions
Diabetes medications — additive. Anticoagulants (cassia especially — coumarin). Hepatotoxic drugs (with cassia).
Contraindications
Liver disease (avoid cassia entirely; Ceylon is safe). Pregnancy (high doses).
Lab markers
Fasting glucose, HbA1c, lipid panel. LFTs if running cassia long-term.
Food sources
Ceylon cinnamon in cooking, baking, oats, coffee. Even 1 tsp/day in food provides some benefit.

Pairs with

Berberine, chromium, alpha-lipoic acid (blood sugar stack).