Ceylon Cinnamon (Cinnamomum verum)New
A spice-derived extract studied for modest improvements in fasting glucose and HbA1c, mainly in people with type 2 diabetes. Ceylon ("true") cinnamon contains far less coumarin than the cheaper cassia types, which matters for long-term use. Most pooled data come from mixed cinnamon species, so Ceylon-specific effect sizes are less certain.
Mechanism of Action
Cinnamaldehyde and polyphenolic procyanidins are proposed to enhance insulin receptor signalling (including GLUT4 translocation), slow gastric emptying and inhibit intestinal alpha-glucosidase, blunting post-meal glucose rises. Antioxidant and anti-inflammatory effects are also proposed. Most mechanisms are from cell and animal work.
Dosing Protocol
1g per day of powder (typically 1-2 g)
Standard starting dose based on research
Therapeutic Range
0.5
Minimum
3
Maximum
With meals, once or divided twice daily; 1-2 g with the largest carbohydrate meal is a common approach
Cycling Protocol
No established cycling. Reassess glycaemic markers (fasting glucose, HbA1c) after 8-12 weeks and stop if no benefit
Dosages are general guidelines. Individual requirements vary based on body weight, health status, and specific goals. Start with lower doses and adjust based on response.
Benefits
Primary Benefits
- Modest reductions in fasting blood glucose and HbA1c in adults with type 2 diabetes (pooled RCTs of mixed cinnamon species)
- Possible reduction in insulin resistance (HOMA-IR) in capsule trials at doses of 2 g/day or less
Secondary Benefits
Safety Information
Contraindications
Do not use if any of the following apply:
- •Chronic liver disease or elevated liver enzymes (especially with cassia cinnamon)
- •Pregnancy at supplement doses (insufficient data)
- •Planned surgery within 2 weeks (blood-glucose effects)
- •Known cinnamon allergy
Drug/Supplement Interactions
May interact with the following. Consult a healthcare provider before combining:
Potential Side Effects
Some users may experience:
This is not a complete list of interactions or side effects. Individual responses vary. Always start with the lowest effective dose and monitor your response. Report any adverse effects to your healthcare provider.
Quality Markers
Look for these specific quality indicators when sourcing this compound:
- Label specifies Cinnamomum verum / zeylanicum, not "cinnamon" or cassia
- Low-coumarin: independent testing showing coumarin well below cassia levels
- Third-party tested for heavy metals (lead contamination has been reported in some ground cinnamon)
- Standardised extract or stated g of powder per capsule
Trusted Certifications
Note: Supplement quality varies dramatically between brands. Cheap supplements often contain fillers, incorrect doses, or contaminants. Investing in quality products from reputable manufacturers is essential for safety and efficacy.
Evidence Profile
Evidence Score
4/10
Emerging/Anecdotal
Limited clinical data, primarily mechanistic studies or user reports
Evidence Scale
8-10
Strong
5-7
Moderate
1-4
Emerging
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