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Cinnamon
Cinnamon has two stories and they need to be told in this order.
- Evidence
- Mixed Evidence
- Category
- Weight Management
- Best form
- Ceylon cinnamon (Cinnamomum verum, also sold as Cinnamomum zeylanicum or 'true cinnamon') for chronic daily supplementation - coumarin content under 0.1 mg/g, roughly 50-100x lower than Cassia
- Effective dose
- 1-6 g/day of cinnamon powder or equivalent extract. The Khan 2003, Crawford 2009, and Mang 2006 trials used 1-6 g/day Cassia (Crawford 2009 at 1 g/day, Mang 2006 at 3 g/day aqueous extract, Khan 2003 at 1, 3, or 6 g/day). The Allen 2013 and Akilen 2012 meta-analyses pooled across this range. For Cassia, anything above roughly 1 g/day chronic will likely exceed the EFSA coumarin tolerable daily intake
- Lab tested
- 3 of 8 products
- Category
- Weight Management
- Best form
- Ceylon cinnamon (Cinnamomum verum, also sold as Cinnamomum zeylanicum or 'true cinnamon') for chronic daily supplementation - coumarin content under 0.1 mg/g, roughly 50-100x lower than Cassia
- Effective dose
- 1-6 g/day of cinnamon powder or equivalent extract. The Khan 2003, Crawford 2009, and Mang 2006 trials used 1-6 g/day Cassia (Crawford 2009 at 1 g/day, Mang 2006 at 3 g/day aqueous extract, Khan 2003 at 1, 3, or 6 g/day). The Allen 2013 and Akilen 2012 meta-analyses pooled across this range. For Cassia, anything above roughly 1 g/day chronic will likely exceed the EFSA coumarin tolerable daily intake
- Lab tested
- 3 of 8 products
Key takeaways
- →Ceylon (Cinnamomum verum) and Cassia (Cinnamomum cassia, including Saigon and Korintje) are different species. Cassia contains 50-100x more coumarin, a hepatotoxin. For daily long-term use, pay the premium for Ceylon.
- →If the bottle does not specify the species, assume Cassia. Most US grocery cinnamon and most supplement-aisle 'cinnamon' is Cassia.
- →Fasting glucose effect is real but modest: meta-analyses pool a ~24 mg/dL reduction in type 2 diabetics. HbA1c effect is smaller and inconsistent. Smaller effect than berberine.
- →Trial doses ran 1-6 g/day of Cassia. At those doses, Cassia coumarin exposure regularly exceeds the EFSA tolerable daily intake (~7 mg/day for a 70 kg adult). Ceylon at the same gram doses delivers negligible coumarin.
- →Real drug interactions with antidiabetic medications (additive glucose lowering) and modest antiplatelet effect; flag with physician before adding to insulin, sulfonylurea, metformin, or anticoagulant regimens.
What Is Cinnamon?
Cinnamon has two stories and they need to be told in this order. The first is what variety you are buying, because Ceylon and Cassia are different species with a 50-to-100-fold difference in coumarin content, and coumarin is a hepatotoxin at chronic supplemental doses. The second is the actual glucose evidence, which is real but modest.
Start with the species question. "Cinnamon" in the US grocery aisle and in roughly 90% of supplement bottles is Cassia (Cinnamomum cassia, sometimes labeled Cinnamomum aromaticum, plus Saigon and Korintje subtypes that are also Cassia). Ceylon cinnamon (Cinnamomum verum, also written as Cinnamomum zeylanicum) is the original "true" cinnamon and comes almost exclusively from Sri Lanka. Woehrlin 2010, analyzing 47 cinnamon samples from the German retail market, found coumarin content in Cassia bark ranging from 0.9 to 12.2 mg/g with a mean around 3-6 mg/g, while Ceylon samples ran under 0.02 mg/g. Abraham 2010's toxicology review summarized the EFSA tolerable daily intake at 0.1 mg coumarin per kg body weight, which works out to about 7 mg/day for a 70 kg adult. A teaspoon of grocery-store Cassia is roughly 2.5 g and can deliver 7-30 mg of coumarin by itself. Daily Cassia supplementation at the 1-6 g doses used in the diabetes trials regularly exceeds this. Coumarin causes dose-dependent hepatotoxicity in humans (case reports of cholestatic hepatitis exist) and has been associated with hepatocellular carcinoma in long-term rat studies. The EFSA position is that the TDI can be exceeded short-term without lasting harm, but chronic exceedance is exactly the use case for daily cinnamon capsules.
This is the most actionable consumer decision in this profile: if you are going to take cinnamon daily for months, pay the 2-3x premium for Ceylon. If the label does not specify the species, default to assuming Cassia and treat accordingly. Saigon cinnamon, sometimes marketed as premium, is one of the higher-coumarin Cassia variants and is a poor pick for daily supplementation despite its strong flavor.
Now the glucose evidence. Allen 2013 in Annals of Family Medicine pooled 10 randomized controlled trials covering 543 patients with type 1 or type 2 diabetes and found cinnamon reduced fasting plasma glucose by 24.6 mg/dL on average, alongside small reductions in LDL, triglycerides, and total cholesterol. HbA1c effects were smaller, less consistent, and not statistically significant in the pooled analysis. Akilen 2012 in Clinical Nutrition reached a similar conclusion: meta-analyzed glucose and HbA1c reductions in type 2 diabetes, with the fasting glucose effect more reproducible than HbA1c. The originating trials are Khan 2003 (Diabetes Care, n=60 Pakistani type 2 diabetics, 1-6 g/day Cassia for 40 days, significant reductions in fasting glucose, triglycerides, LDL, and total cholesterol), Mang 2006 (European Journal of Clinical Investigation, n=79 German type 2 diabetics, 3 g/day aqueous Cassia extract for 4 months, modest fasting glucose reduction without HbA1c improvement), and Crawford 2009 (J Am Board Fam Med, n=109 US type 2 diabetics, 1 g/day Cassia for 90 days, HbA1c reduced 0.83% versus 0.37% in control). Davis 2011 in J Medicinal Food pooled fasting glucose specifically and confirmed the directionality.
So the evidence supports a structure/function claim around fasting glucose, with the caveats that: the effect is modest (smaller than berberine's metformin-non-inferior signal), HbA1c effects are inconsistent, the trials are mostly small and short, several were in non-Western populations or specific Cassia subtypes, and the published trials almost exclusively used Cassia. Whether Ceylon delivers the same metabolic effect at the same gram dose is plausible (the polyphenol fractions are similar) but not as directly supported. The Mang 2006 aqueous extract dataset is the cleanest because the water-extraction process strips most coumarin while keeping the active polyphenols, but that specific extract (Cinnulin PF) is not what is in most consumer bottles.
Honest position: cinnamon is not a primary tool for diabetes. The fasting glucose signal is real but the HbA1c signal is weak, the trials are imperfect, and the Cassia-vs-Ceylon safety arithmetic argues strongly against high chronic Cassia doses. If you want a botanical with stronger metabolic evidence, berberine is non-inferior to metformin in head-to-head data and has a much larger effect size. If you want gymnemic acid mechanisms for sugar cravings, gymnema is the right tool. Cinnamon's best honest use case is as a modest adjunct in a broader metabolic protocol, taken as Ceylon, at moderate gram doses, with realistic expectations about effect size.
Does It Work? The Evidence
How A-F grades workFasting blood glucose reduction in type 2 diabetes
Allen 2013 meta-analysis (10 RCTs, n=543): fasting plasma glucose reduced 24.6 mg/dL (95% CI -40.5 to -8.7); Davis 2011 meta-analysis confirmed fasting glucose effect; Khan 2003 (n=60, 1-6 g/day Cassia x 40 days): 18-29% fasting glucose reduction across all dose arms
HbA1c reduction in type 2 diabetes
Crawford 2009 (n=109 T2D, 1 g/day Cassia x 90 days): HbA1c reduced 0.83% in cinnamon group vs 0.37% in usual-care control; Akilen 2012 meta-analysis: pooled HbA1c reduction in T2D; Allen 2013 meta-analysis: HbA1c effect did not reach statistical significance overall
LDL and total cholesterol reduction
Allen 2013 meta-analysis: small but significant reductions in LDL and total cholesterol alongside glucose effects; Khan 2003: LDL, total cholesterol, and triglyceride reductions across 1, 3, and 6 g/day Cassia arms
Triglyceride reduction
Allen 2013: pooled triglyceride reduction; Khan 2003: 23-30% triglyceride reduction at 1-6 g/day Cassia
Blood pressure reduction in prediabetes / T2D
Akilen 2013 (Nutrition): short-term cinnamon dosing reduced systolic and diastolic blood pressure in prediabetic and T2D patients; effect small and short-term
Fasting glucose in non-diabetic adults
Davis 2011 meta-analysis included non-diabetic subgroups with smaller and less consistent effects; cinnamon's glucose effect is more pronounced in dysglycemic populations
Insulin sensitivity / weight loss in non-diabetic adults
No consistent evidence that cinnamon meaningfully reduces body weight, waist circumference, or improves insulin sensitivity in healthy adults; mechanism plausible but not demonstrated
Coumarin hepatotoxicity at chronic Cassia doses
Abraham 2010 (Mol Nutr Food Res) toxicology review: EFSA tolerable daily intake set at 0.1 mg/kg/day; Woehrlin 2010 (J Agric Food Chem): Cassia bark coumarin 0.9-12.2 mg/g; published case reports of cinnamon-supplement-associated cholestatic hepatitis; risk negligible with Ceylon
| Grade | Claimed Benefit | Key Studies | Our Verdict |
|---|---|---|---|
| B | Fasting blood glucose reduction in type 2 diabetes | Allen 2013 meta-analysis (10 RCTs, n=543): fasting plasma glucose reduced 24.6 mg/dL (95% CI -40.5 to -8.7); Davis 2011 meta-analysis confirmed fasting glucose effect; Khan 2003 (n=60, 1-6 g/day Cassia x 40 days): 18-29% fasting glucose reduction across all dose arms | Supported |
| C | HbA1c reduction in type 2 diabetes | Crawford 2009 (n=109 T2D, 1 g/day Cassia x 90 days): HbA1c reduced 0.83% in cinnamon group vs 0.37% in usual-care control; Akilen 2012 meta-analysis: pooled HbA1c reduction in T2D; Allen 2013 meta-analysis: HbA1c effect did not reach statistical significance overall | Conflicted |
| C | LDL and total cholesterol reduction | Allen 2013 meta-analysis: small but significant reductions in LDL and total cholesterol alongside glucose effects; Khan 2003: LDL, total cholesterol, and triglyceride reductions across 1, 3, and 6 g/day Cassia arms | Early Signal |
| C | Triglyceride reduction | Allen 2013: pooled triglyceride reduction; Khan 2003: 23-30% triglyceride reduction at 1-6 g/day Cassia | Early Signal |
| C | Blood pressure reduction in prediabetes / T2D | Akilen 2013 (Nutrition): short-term cinnamon dosing reduced systolic and diastolic blood pressure in prediabetic and T2D patients; effect small and short-term | Early Signal |
| D | Fasting glucose in non-diabetic adults | Davis 2011 meta-analysis included non-diabetic subgroups with smaller and less consistent effects; cinnamon's glucose effect is more pronounced in dysglycemic populations | Not There Yet |
| D | Insulin sensitivity / weight loss in non-diabetic adults | No consistent evidence that cinnamon meaningfully reduces body weight, waist circumference, or improves insulin sensitivity in healthy adults; mechanism plausible but not demonstrated | Not There Yet |
| B | Coumarin hepatotoxicity at chronic Cassia doses | Abraham 2010 (Mol Nutr Food Res) toxicology review: EFSA tolerable daily intake set at 0.1 mg/kg/day; Woehrlin 2010 (J Agric Food Chem): Cassia bark coumarin 0.9-12.2 mg/g; published case reports of cinnamon-supplement-associated cholestatic hepatitis; risk negligible with Ceylon | Supported |
How to Choose: Forms, Doses & What Matters
Clinical dose: 1-6 g/day of cinnamon powder or equivalent extract. The Khan 2003, Crawford 2009, and Mang 2006 trials used 1-6 g/day Cassia (Crawford 2009 at 1 g/day, Mang 2006 at 3 g/day aqueous extract, Khan 2003 at 1, 3, or 6 g/day). The Allen 2013 and Akilen 2012 meta-analyses pooled across this range. For Cassia, anything above roughly 1 g/day chronic will likely exceed the EFSA coumarin tolerable daily intake; for Ceylon at the same gram doses, coumarin exposure is negligible
Best forms: Ceylon cinnamon (Cinnamomum verum, also sold as Cinnamomum zeylanicum or 'true cinnamon') for chronic daily supplementation - coumarin content under 0.1 mg/g, roughly 50-100x lower than Cassia, Cassia cinnamon (Cinnamomum cassia, Cinnamomum aromaticum, also Saigon and Korintje varieties) is the form used in most published glucose trials, but coumarin runs 5-12 mg/g; acceptable for short courses only, Standardized Cassia extracts that have been water-extracted (the Mang 2006 trial used Cinnulin PF, an aqueous extract that depletes lipid-soluble coumarin) reduce hepatotoxicity risk while retaining the polyphenol fraction, Whole-bark capsules over loose ground powder for dose-accuracy and to avoid the variable coumarin content of grocery-store Cassia
For metabolic support: 1-3 g/day of Ceylon cinnamon powder or capsule equivalent, taken with the largest carbohydrate-containing meal of the day to coincide with postprandial glucose. Crawford 2009 dosed 1 g/day; Mang 2006 dosed 3 g/day of aqueous extract; Khan 2003 found dose-response from 1 to 6 g/day Cassia but the safety arithmetic argues for the lower end with Ceylon. If using Cassia (the form most trials used), limit to short courses of 6-8 weeks or use a water-extracted standardized form like Cinnulin PF that has reduced coumarin content. Capsule formulations are easier to dose accurately than loose powder. Allow 8-12 weeks before judging glycemic effects via fasting glucose, HbA1c, and lipid panel. If you take diabetes medications, monitor blood sugar more closely for the first month and coordinate with your physician. Stop if you develop right-upper-quadrant pain, jaundice, dark urine, or unexplained fatigue, all of which can signal cholestatic injury.
Who Should Take Cinnamon?
Adults with prediabetes or type 2 diabetes who want an evidence-aware botanical adjunct to standard care, taken as Ceylon cinnamon at 1-3 g/day, with physician coordination if on glucose-lowering medications. People with mildly elevated fasting glucose looking for a low-risk additive intervention alongside diet and exercise. Adults already cooking with substantial cinnamon who want the species-correct supplement form rather than relying on variable-quality kitchen powder. People with elevated LDL or triglycerides looking for a non-pharmaceutical adjunct with modest lipid signal. Anyone choosing between cinnamon and a stronger glycemic botanical: berberine has larger metabolic effect; cinnamon is the gentler, lower-friction option for milder glucose elevations.
Who Should Avoid It?
Not for everyone
Side Effects & Safety
Product Scores
8 products scored on dosing accuracy, third-party testing, cost per effective dose, and label transparency.
The Scorecard: 8 Products Compared
Full Spectrum True Cinnamon 300 mg, 120 Capsules (Ceylon)
Swanson
$11.99 ÷ 120 days at 300mg/day (1 serving × 300mg)
The strongest mainstream-brand combination of Ceylon species disclosure, transparent sourcing, and competitive per-mg pricing in the lineup
Prices checked 2026-05-18. Cost shown is per clinically effective daily dose, not per pill.
Ceylon Cinnamon Capsules 1,500 mg, 225 Vegan Capsules
Purely Holistic
$19.99 ÷ 111 days at 1500mg/day (1 serving × 1500mg)
Strong value pick if you want Ceylon at the Crawford trial dose without paying mainstream-brand prices; verify the Sri Lankan sourcing claim independently if it matters to you
Prices checked 2026-05-18. Cost shown is per clinically effective daily dose, not per pill.
Organic Ceylon Cinnamon 1,200 mg, 120 Capsules (USDA Certified)
NutriFlair
$23.95 ÷ 60 days at 1200mg/day (1 serving × 1200mg)
Choose NutriFlair over Purely Holistic if USDA Organic certification is a decision factor; otherwise Purely Holistic delivers the same Ceylon species at lower per-day cost
Prices checked 2026-05-18. Cost shown is per clinically effective daily dose, not per pill.
Cinnamon Bark 600 mg, 240 Veg Capsules
NOW Foods$19.99 ÷ 250 days at 600mg/day (1 serving × 600mg)
Reasonable budget pick for short-term use, but for chronic daily dosing the species ambiguity is a real downside - prefer a Ceylon-specific product below
Prices checked 2026-05-18. Cost shown is per clinically effective daily dose, not per pill.
Organic Ceylon Cinnamon Powder, 1 lb (Ground)
Anthony's
$13.99 ÷ 466 days at 1000mg/day (1 serving × 1000mg)
Best pick if you cook with cinnamon and want a single Sri Lankan Ceylon source - dosing by 1/3 teaspoon daily over yogurt, oatmeal, or coffee gets you to the Crawford 2009 dose at the lowest per-day cost in the category
Prices checked 2026-05-18. Cost shown is per clinically effective daily dose, not per pill.
Full Potency Cinnamon, 100 Vegetable Capsules
Solgar$22.00 ÷ 100 days at 500mg/day (1 serving × 500mg)
Honest, filler-free Cassia option for short courses; for chronic dosing the Swanson Ceylon profile is the better safety arithmetic at lower cost
Prices checked 2026-05-18. Cost shown is per clinically effective daily dose, not per pill.
Organic Ceylon Cinnamon Supplement, 90 Capsules
Ceylon Cinnamon Shop
$19.99 ÷ 45 days at 1200mg/day (1 serving × 1200mg)
Choose this only if the specialty single-focus Ceylon brand positioning matters to you - the per-day cost and lighter testing program make it harder to justify over the Swanson or Purely Holistic options
Prices checked 2026-05-18. Cost shown is per clinically effective daily dose, not per pill.
Full Comparison
| Category | Full Spectrum True Cinnamon 300 mg, 120 Capsules (Ceylon) Swanson | Ceylon Cinnamon Capsules 1,500 mg, 225 Vegan Capsules Purely Holistic | Organic Ceylon Cinnamon 1,200 mg, 120 Capsules (USDA Certified) NutriFlair | Cinnamon Bark 600 mg, 240 Veg Capsules NOW Foods | Cinnamon Premium Extract, 8% Flavonoids, 120 Vegan Capsules Nature's Way | Organic Ceylon Cinnamon Powder, 1 lb (Ground) Anthony's | Full Potency Cinnamon, 100 Vegetable Capsules Solgar | Organic Ceylon Cinnamon Supplement, 90 Capsules Ceylon Cinnamon Shop |
|---|---|---|---|---|---|---|---|---|
| Brand Score | 84/100Winner | 81/100 | 80/100 | 79/100 | 78/100 | 77/100 | 76/100 | 75/100 |
| Dosing & Form | 20/25 | 22/25Winner | 22/25 | 19/25 | 20/25 | 18/25 | 18/25 | 19/25 |
| Purity | 18/25 | 16/25 | 16/25 | 19/25Winner | 17/25 | 17/25 | 18/25 | 15/25 |
| Value | 23/25Winner | 22/25 | 21/25 | 22/25 | 21/25 | 22/25 | 18/25 | 19/25 |
| Transparency | 23/25Winner | 21/25 | 21/25 | 19/25 | 20/25 | 20/25 | 22/25 | 22/25 |
| Cost/Day | $0.10 | $0.18 | $0.40 | $0.08 | $0.20 | $0.03Winner | $0.22 | $0.44 |
| Dose/Serving | 300mg | 1500mg | 1200mg | 600mg | 500mg | 1000mg | 500mg | 1200mg |
| Form | Ceylon cinnamon (Cinnamomum verum) whole bark powder, vegetable capsule | Ceylon cinnamon (Cinnamomum verum) bark powder, vegan capsule | Organic Ceylon cinnamon (Cinnamomum verum) bark powder, vegetable capsule | Cinnamon bark powder, vegetable capsule | Cassia cinnamon bark extract standardized to 8% flavonoids, vegan capsule | Bulk Ceylon cinnamon (Cinnamomum verum) ground bark powder | Cassia cinnamon bark powder (no fillers), vegetable capsule | Organic Ceylon cinnamon (Cinnamomum verum) bark powder, vegetable capsule |
| Third-Party Tested | ✓ Yes | No | No | ✓ Yes | ✓ Yes | No | No | No |
| Proprietary Blend | No | No | No | No | No | No | No | No |
Frequently Asked Questions
What is the difference between Ceylon and Cassia cinnamon?
They are different species in the same plant genus. Cassia (Cinnamomum cassia, plus the Saigon and Korintje varieties) is the cinnamon in roughly 90% of US grocery and supplement products - cheap, dark, strong-flavored, and high in coumarin (typically 3-6 mg per gram, sometimes up to 12 mg/g per Woehrlin 2010's market survey). Ceylon (Cinnamomum verum, also written as Cinnamomum zeylanicum) is the original 'true' cinnamon from Sri Lanka - milder, more delicate, and very low in coumarin (under 0.1 mg/g, often under 0.02 mg/g). Coumarin is a hepatotoxin at chronic doses. The EFSA tolerable daily intake works out to about 7 mg/day for a 70 kg adult, which a teaspoon of Cassia can exceed by itself. For daily supplementation over months, the species difference is the most important variable on the label.
How much does cinnamon actually lower blood sugar?
Modestly. The Allen 2013 meta-analysis of 10 trials in 543 type 1 and type 2 diabetics found an average fasting plasma glucose reduction of about 24.6 mg/dL. HbA1c reductions in the same meta-analysis were smaller and did not reach statistical significance overall, though individual trials like Crawford 2009 showed HbA1c improvement at 1 g/day Cassia. This is real but smaller than the effect from berberine, which has been shown non-inferior to metformin in head-to-head trials. Cinnamon is reasonable as a gentle adjunct, not as a primary intervention for diabetes.
Is the cinnamon in my grocery aisle Ceylon or Cassia?
Almost certainly Cassia unless the label specifically says 'Ceylon' or 'Cinnamomum verum.' US food labeling does not require species disclosure, so anything labeled simply 'cinnamon' is allowed to be Cassia. Saigon cinnamon, sometimes marketed as a premium variety, is one of the higher-coumarin Cassia types. Korintje is also Cassia. Ceylon usually says so on the front of the package because it costs 2-3x more and the species is the selling point. If you bake or sprinkle on oatmeal occasionally, Cassia is fine. If you are taking grams daily as a supplement, switch to Ceylon.
How much coumarin is in a daily cinnamon supplement?
Depends entirely on the species. A 1 gram Cassia dose at typical retail coumarin content (3-6 mg/g) delivers roughly 3-6 mg of coumarin per day; at the high end of Woehrlin 2010's analyzed samples (12 mg/g) it could deliver 12 mg/day from a 1 g dose alone. The EFSA tolerable daily intake is 0.1 mg/kg body weight, so about 7 mg/day for a 70 kg adult. A 3 g/day Cassia dose, like the one Mang 2006 used, would routinely exceed this. The same 1-3 g/day dose of Ceylon delivers under 0.3 mg/day of coumarin and is well under the TDI. This is the central reason to switch species if you are dosing chronically.
Is cinnamon as effective as berberine for blood sugar?
No. Berberine has a head-to-head non-inferiority trial against metformin (Zhang 2008) and meta-analyses across 14+ trials showing consistent and large HbA1c reductions. Cinnamon's strongest signal is on fasting glucose at roughly 24 mg/dL reduction in diabetics, with weaker and less consistent HbA1c effect. If your priority is metabolic effect size, berberine is the better-evidenced botanical. Cinnamon's advantages are that it is gentler, cheaper, more familiar, has fewer drug interactions, and works better as a casual daily addition than as a serious metabolic intervention.
What about Saigon cinnamon - is it better or worse?
Worse for daily supplementation. Saigon cinnamon (also called Vietnamese cinnamon, Cinnamomum loureiroi) is a Cassia variant with one of the higher coumarin contents in the family. It is delicious in baking because the cinnamaldehyde content is also high and the flavor is intense, but those same lipid-soluble compounds include the hepatotoxic coumarin. If you have a Saigon-labeled supplement and are taking it daily, that is the worst combination on the shelf - high coumarin, no glucose-evidence advantage over plain Cassia. Use Saigon in the kitchen, not in capsules.
Can I just take more Ceylon since it has less coumarin?
Yes, within reason. Ceylon at 2-4 g/day is well under any coumarin concern because the coumarin density is 50-100x lower. The published trials used Cassia at 1-6 g/day, and there is no specific dose-response trial in Ceylon to confirm that Ceylon at the same gram dose produces the same glucose effect, but the polyphenol fractions responsible for the metabolic effect are similar enough across species that pharmacological extrapolation is reasonable. Practical recommendation: 1-3 g/day Ceylon, taken with the largest meal, for 8-12 weeks before reassessing.
How long does it take cinnamon to work for blood sugar?
The trials that found benefit ran 40 days (Khan 2003) to 4 months (Mang 2006) to 90 days (Crawford 2009). A reasonable baseline is 8-12 weeks before re-measuring fasting glucose, HbA1c, and a lipid panel. Effects on fasting glucose appear first; HbA1c effects, when present, take longer because the marker reflects average glucose over the preceding 2-3 months. If 12 weeks of consistent dosing produces no fasting-glucose improvement, cinnamon is unlikely to be doing much for you and a different intervention is warranted.
Are cinnamon capsules safer than ground cinnamon from the spice aisle?
Sometimes. Capsules give you accurate dosing and many supplement brands disclose the species. Grocery-store ground cinnamon does not disclose species, has variable coumarin content from batch to batch, and is dosed by 'a sprinkle' rather than a gram. For chronic daily supplementation, a capsule that says 'Ceylon' or 'Cinnamomum verum' is the most controlled option. That said, cooking with Ceylon powder is an equally fine way to get the polyphenol fraction if you cook with cinnamon regularly and trust your source. The format matters less than the species and the dose.
Sources
- Allen RW, Schwartzman E, Baker WL, Coleman CI, Phung OJ. Cinnamon use in type 2 diabetes: an updated systematic review and meta-analysis. Ann Fam Med. 2013;11(5):452-459.
- Akilen R, Tsiami A, Devendra D, Robinson N. Cinnamon in glycaemic control: systematic review and meta analysis. Clin Nutr. 2012;31(5):609-615.
- Akilen R, Tsiami A, Robinson N. Efficacy and safety of 'true' cinnamon (Cinnamomum zeylanicum) as a pharmaceutical agent in diabetes: a systematic review and meta-analysis. Diabet Med. 2013;30(4):505-507.
- Khan A, Safdar M, Ali Khan MM, Khattak KN, Anderson RA. Cinnamon improves glucose and lipids of people with type 2 diabetes. Diabetes Care. 2003;26(12):3215-3218.
- Crawford P. Effectiveness of cinnamon for lowering hemoglobin A1C in patients with type 2 diabetes: a randomized, controlled trial. J Am Board Fam Med. 2009;22(5):507-512.
- Mang B, Wolters M, Schmitt B, Kelb K, Lichtinghagen R, Stichtenoth DO, Hahn A. Effects of a cinnamon extract on plasma glucose, HbA, and serum lipids in diabetes mellitus type 2. Eur J Clin Invest. 2006;36(5):340-344.
- Davis PA, Yokoyama W. Cinnamon intake lowers fasting blood glucose: meta-analysis. J Med Food. 2011;14(9):884-889.
- Abraham K, Wöhrlin F, Lindtner O, Heinemeyer G, Lampen A. Toxicology and risk assessment of coumarin: focus on human data. Mol Nutr Food Res. 2010;54(2):228-239.
- Woehrlin F, Fry H, Abraham K, Preiss-Weigert A. Quantification of flavoring constituents in cinnamon: high variation of coumarin in cassia bark from the German retail market and in authentic samples from Indonesia. J Agric Food Chem. 2010;58(19):10568-10575.
FDA Disclaimer: These statements have not been evaluated by the Food and Drug Administration. The products discussed on this page are not intended to diagnose, treat, cure, or prevent any disease. Always consult with a qualified healthcare professional before starting any supplement regimen.