Does cinnamon lower blood sugar?
Somewhat — in type 2 diabetes, cinnamon lowered fasting blood glucose by about 24 mg/dL across 10 trials. But it didn't move HbA1c, the long-term marker, and results varied a lot. For daily use, choose Ceylon cinnamon, not cassia, because of coumarin.
What the evidence supports
What it doesn't do
- ✗ Improve HbA1c — the long-term marker didn't change1
- ✗ Give a reliable effect — heterogeneity between trials was very high
- ✗ Replace diabetes medication, or help in a proven way if you're not diabetic
Where this comes from
- What the human evidence shows
- The anchor is a 2013 meta-analysis of 10 randomised trials in 543 people with type 2 diabetes, using cinnamon doses from 120 mg to 6 g a day for 4 to 18 weeks.1 Cinnamon significantly lowered fasting plasma glucose (−24.6 mg/dL), and also total cholesterol, LDL and triglycerides, and raised HDL a little. But it produced no significant change in HbA1c, and heterogeneity between trials was very high — the reviewers explicitly noted this "may limit the ability to apply these results to patient care," because the best dose and duration are unclear.
- The Ceylon-versus-cassia safety point
- This one matters. Most supermarket cinnamon is cassia, which is high in coumarin — a natural compound that can harm the liver at regular high intakes; a teaspoon of cassia can exceed the tolerable daily coumarin amount for a smaller adult. Ceylon, or "true", cinnamon contains only trace coumarin. As an occasional sprinkle, ordinary cinnamon is fine, but for daily use — and certainly for larger, supplement-style doses — use Ceylon, and keep to culinary amounts.
- Where the evidence stops
- Two honest limits. First, the effect is on fasting glucose only; the fact that HbA1c did not move means we can't say cinnamon improves overall blood-sugar control, just a morning snapshot. Second, the evidence is in people with type 2 diabetes — there's little to say it helps blood sugar in people without it. Cinnamon is a pleasant, low-risk spice with a modest, uncertain glucose signal, not a treatment. We recommend no cinnamon supplement.
The practical version: enjoy cinnamon on porridge, fruit or coffee — using Ceylon if you have it daily — and it may give your fasting glucose a small nudge. Don't rely on it to manage diabetes: it didn't improve HbA1c, the effect is inconsistent, and it's no substitute for proper care. Skip cinnamon capsules; we recommend no supplement, and we sell nothing.
At a glance
Sources
- Allen RW, Schwartzman E, Baker WL, Coleman CI, Phung OJ. Cinnamon use in type 2 diabetes: an updated systematic review and meta-analysis. Annals of Family Medicine, 2013. PMC3767714 — 10 RCTs, 543 patients; fasting glucose −24.6 mg/dL, lipids improved, no significant HbA1c change; high heterogeneity.
Bottom line for you
Cinnamon can give fasting blood sugar a modest nudge in people with type 2 diabetes — about 24 mg/dL in the pooled trials — and it's a low-risk, pleasant spice to include. If you use it daily, make it Ceylon cinnamon rather than cassia, to keep coumarin low and protect your liver.
Just don't over-read it. It didn't improve HbA1c, the results varied widely, and there's little evidence it helps if you don't have diabetes — so it's a minor extra, not a treatment, and never a reason to change diabetes medication. We recommend no cinnamon supplement, and we sell nothing.
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Educational information based on peer-reviewed human studies. Not medical advice — manage diabetes with your clinician, and take care with daily cassia cinnamon if you have liver concerns. AntiAgingGreens never sells or recommends supplements. We report what the evidence shows — and where it stops.