Compound or practice · Supplement
Cinnamon
A modest, inconsistent glucose helper — and a reminder that cassia cinnamon's coumarin can stress the liver at high doses.
- Overall grade
- Grade C
- Last revised
- 1
- graded outcome
- 0
- references listed
A structured monograph in Prometheus's bundled library. Its grades are the monograph's own reading of the evidence, not a peer-reviewed review.
1 at grade C — 1 graded row
What is known
Each outcome with its grade (how strong the evidence is, A to D), the size of the effect where the entry records one, and how often studies agree.
- Fasting glucoseEvidence grade C
Inconsistent
Smallmixed
What is uncertain
Read off the same rows as above. Nothing here is added that the entry does not itself record.
- Thin evidence: Fasting glucose (grade C).
- Caution with Metformin: Additive glucose lowering.
Interactions
Documented pairings with supplements and medicines. A medicine on this list is a conversation for whoever prescribes it.
MetforminCaution
Additive glucose lowering.
The evidence in words
What it is
Cinnamon (cassia or Ceylon) is a spice studied for blood-glucose control. Cassia is common and cheap; Ceylon is lower in coumarin.
How it works
Cinnamon polyphenols may improve insulin sensitivity and slow gastric emptying, modestly affecting post-meal glucose.
What the evidence shows
Meta-analyses show small, inconsistent reductions in fasting glucose and lipids — real for some, negligible for others, and not a substitute for glucose-lowering therapy. The safety caveat: cassia cinnamon contains coumarin, which is hepatotoxic in high chronic doses; Ceylon avoids this.
How to use it
1–2 g/day; prefer Ceylon cinnamon for regular supplemental use to limit coumarin.
Safety & interactions
High-dose cassia coumarin can stress the liver; additive glucose lowering with diabetes drugs. metformin — Additive glucose lowering.
Bottom line
A mild, unreliable glucose nudge. If you use it daily, choose Ceylon over cassia to avoid the coumarin liver risk.
How it is used
As the entry records it, from the studies it summarises. Not a recommendation for you — doses that suit a trial population may not suit you.
- Standard
- 1–2 g/day; prefer Ceylon.
Related reading
Entries that share this one's tags or conditions.
- Cinnamon for Fasting glucoseEvidence grade C — InconsistentEvidence grade C
- Cinnamon: dosage and how to take it1–2 g/day; prefer Ceylon.Evidence grade C
- Cinnamon: side effects, safety & interactionsHigh-dose cassia coumarin can stress the liver; additive glucose lowering with diabetes drugs.Evidence grade C
- Alpha-Lipoic AcidAn antioxidant with genuine evidence for diabetic neuropathy symptoms and modest insulin-sensitivity effects.Evidence grade B
Sources
This entry lists no references of its own.
Last revised . A grade is this entry's reading of the evidence, not medical advice.