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Dietary supplement

Cinnamon 1000 mg Ingredients & Drug Interactions

by 21st Century

Cinnamon 1000 mg label
See full label image
Capsule Category: Botanical
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Cinnamon 1000 mg against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Moderate

Cinnamon 1000 mg is a dietary supplement by 21st Century with 1 active ingredient. Its ingredients are commonly taken for blood sugar support, digestive upset, antioxidant support.Based on those ingredients, 442 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Cinnamon. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Cinnamon 1000 mg by 21st Century

Ask about any prescription or over-the-counter medication and we check it for interactions with Cinnamon 1000 mg by 21st Century — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Cinnamon 1000 mg by 21st Century

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 11, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

This supplement is just cinnamon — one active ingredient at 1000 mg per capsule. The rest is inactive ingredients: cellulose, rice bran, oat fiber, magnesium silicate, and magnesium stearate (common binders and fillers).

Does it work?

Not established
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Not established

The graded evidence we hold for these ingredients covers different conditions than the ones this product is marketed for, so there's no established rating for its stated use — see Cassia Cinnamon's own graded uses on its monograph.

Why this rating?
  • The label markets this product for: support normal sugar metabolism.
  • We looked for evidence on: Diabetes, Impaired glucose tolerance (prediabetes), blood glucose control, metabolic health.
  • The closest evidence on file: Cassia Cinnamon is rated "Insufficient Reliable Evidence To Rate" for Diabetes (Natural Medicines).
  • Also on file: Cassia Cinnamon is rated "Insufficient Reliable Evidence To Rate" for Impaired glucose tolerance (prediabetes).

The evidence for cinnamon isn't established in the data we hold. For the conditions listed — amenorrhea, angina, common cold, diabetes, diarrhea, and high cholesterol — we have insufficient reliable evidence to rate whether it works.

That doesn't mean it doesn't; it means the research isn't clear enough yet.

The evidence, ingredient by ingredient Cassia Cinnamon

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 1 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Cinnamon from food is generally well tolerated. At supplement doses, though, there's a caution: this product contains coumarin, which can harm the liver if you take high amounts for a long time.

Clinical trials using 360 mg to 12 grams daily for 3 months didn't significantly raise liver enzymes, but very high doses of coumarin (50–7000 mg per day) have caused liver damage in humans that reversed once the coumarin stopped. Rare adverse effects reported include a rash in one trial participant taking 1 gram daily, contact dermatitis in people allergic to cinnamon, and one hypoglycemic seizure (low blood sugar seizure) in someone on this dose — though it's unclear whether the cinnamon caused it.

Side effects, ingredient by ingredient Cassia Cinnamon

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Cassia Cinnamon.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: diabetes medications.
  • For scale: 443 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Double-check this with your pharmacist if you take drugs for liver disease or that can stress the liver (hepatotoxic drugs), or if you're on diabetes medications. Both are Moderate-severity interactions.

Run your exact prescriptions through the checker on this page.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with no established evidence rating for its marketed use. Moderate medication interactions have been identified, and safety information is well characterized.

If you take diabetes or liver-stressing medications, talk with your pharmacist before starting this. The evidence that cinnamon works for any specific condition isn't solid yet.

Food amounts are safe, but supplement doses carry a small risk to your liver over time — keep that in mind for long-term use.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated Sep 24, 2019.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Cinnamon 1000 mg, straight from the product label.

Brand 21st Century
Barcode (UPC) 740985270691
Net contents 120 Vegetarian Capsule(s)
Market status On market
Date entered into DSLD Sep 24, 2019
DSLD ID 206617
Product type Botanical
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Vegetarian, Adult (18 - 50 Years), Gluten Free
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Cinnamon 1000 mg by 21st Century, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
2 Vegetarian Capsule(s)
Maximum serving Sizes:
2 Vegetarian Capsule(s)
Servings per container
60
UPC/BARCODE
740985270691
IngredientAmount% DV
Cinnamon1000 mg--

Other ingredients: Cellulose, Rice Bran, Oat Fiber, Magnesium Silicate, Magnesium Stearate, Contains <2% of

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
Formula

Cinnamon supports normal sugar metabolism when combined with a healthy diet and exercise program.

Cinnamon 1000 mg per serving

Suggested/Recommended/Usage/Directions

Directions: As a dietary supplement, adults take two (2) capsules daily with any meal or as directed by a healthcare provider. Do not exceed recommended dosage.

Precautions

Do not exceed recommended dosage.

Warning: Consult a healthcare provider prior to use if pregnant, nursing, on medications, have a medical condition or are planning a medical procedure.

Stop use and contact a physician if adverse reactions occur.

Keep out of reach of children.

Do not use if product appears to be tampered with or seal is broken.

General Statements

Individual results may vary.

Metabolism Support

Storage

Store at room temperature.

Formulation

No added Sugar, Salt, Yeast, Preservatives, Artificial Flavors or Colors.

100% Vegetarian.

Gluten free

FDA Disclaimer Statement

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

FDA Statement of Identity

Dietary Supplement

Seals/Symbols

Gluten free

Guaranteed quality Laboratory tested

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Cinnamon 1000 mg by 21st Century label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Cinnamon 1000 mg label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in Cinnamon 1000 mg by 21st Century

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size2 Vegetarian Capsule(s) Dosage formCapsule Servings per container60 Amounts shown are per serving.

Cinnamon

Interacts with
442 drugs
1000 mg per serving

Cassia cinnamon is the common, inexpensive cinnamon used in cooking, and it is also taken as a supplement, most often for blood sugar support. The evi...

Cinnamon monograph & interactions

Other (inactive) ingredients: Cellulose, Rice Bran, Oat Fiber, Magnesium Silicate, Magnesium Stearate, Contains <2% of. These complete the product’s ingredient list but are not active constituents.

Interaction report

Cinnamon 1000 mg by 21st Century Drug Interactions

Want to check YOUR meds against Cinnamon 1000 mg?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
442Drugs
442 Moderate

Ingredients driving the most interactions

Cinnamon 442

Individual Drug Interactions

The ingredients in Cinnamon 1000 mg interact with 442 drugs. Click any drug to see the details.

1 of the 1 ingredient in Cinnamon 1000 mg interact with drugs. Each result below shows which ingredient is responsible. Cinnamon

Each ingredient & the kinds of drugs it affects

For each ingredient in Cinnamon 1000 mg with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.

Cinnamon2 drug types · 442 drugs

Antidiabetes Drugs

Theoretically, cassia cinnamon may have additive effects with antidiabetes drugs.
Cassia cinnamon may lower blood glucose levels, and have additive effects in patients treated with antidiabetic agents. Dose adjustments to diabetes medications might be necessary.

Likelihood Possible Evidence B
Hepatotoxic Drugs

Theoretically, large doses of cassia cinnamon might cause additive effects when used with hepatotoxic drugs.
There is some concern that ingesting large amounts of cassia cinnamon for an extended duration might cause hepatotoxicity in some people. Cassia cinnamon contains coumarin, which can cause hepatotoxicity in animal models. In humans, very high doses of coumarin from 50-7000 mg/day can result in hepatotoxicity that resolves when coumarin use is discontinued. Lower amounts might also cause liver problems in sensitive people, such as those with liver disease or those taking potentially hepatotoxic agents.

Likelihood Possible Evidence D
Cinnamon full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Cinnamon 1000 mg, from the product label.

21st Century

See all 21st Century products
Name
21st Century HealthCare, Inc.
Street Address
2119 S. Wilson St.
City
Tempe
State
AZ
ZipCode
85282
Web Address
www.21stcenturyvitamins.com
Pharmacist Counseling Corner

Cinnamon 1000 mg by 21st Century: Common Questions

Does Cinnamon 1000 mg by 21st Century interact with any medications?
Yes. Based on its ingredients, Cinnamon 1000 mg has a known interaction with 442 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Cinnamon 1000 mg contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Is it safe to take this during pregnancy or while breastfeeding?
Cinnamon in food amounts is likely safe. But this is a supplement dose, and the safety data for concentrated doses during pregnancy and breastfeeding is limited. Talk with your doctor or pharmacist for personalized advice before taking it.
What is coumarin and why does it matter?
Coumarin is a natural compound in cassia cinnamon. In large doses taken over a long time, it can harm the liver. Food amounts are fine, but supplement doses are where the concern comes in.
Can this help with my diabetes?
The evidence in our data is insufficient to say whether it works for diabetes. And because cinnamon may lower blood sugar, it could interact with your diabetes drugs — another reason to check with your pharmacist first.
What side effects should I watch for?
Most people tolerate it well. Rarely, a rash or allergic skin reaction can occur (especially if you're sensitive to cinnamon). A case of low blood sugar was reported in one trial, though it's unclear if the cinnamon caused it. Stop and call your pharmacist or doctor if you feel unusual.
How long is it safe to take this supplement?
The safety data is limited for long-term use. Because of coumarin's potential to harm the liver with extended high doses, avoid taking this daily for months without talking to your doctor first — especially at the 1000 mg dose in this product.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Not sure if Cinnamon 1000 mg is safe with your meds?

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Ask a pharmacist

Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

Cinnamon 1000 mg label
Go deeper

The Full Monographs Behind Cinnamon 1000 mg’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Cassia Cinnamon

Interacts with 442 drugs

Cassia cinnamon is the common, inexpensive cinnamon used in cooking, and it is also taken as a supplement, most often for blood sugar support. The evidence for its health benefits is mixed a...

Read the full Cassia Cinnamon monograph →
Sources

Sources & How We Checked

Cinnamon 1000 mg's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 20 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Cassia Cinnamon 20 references
  1. Electronic Code of Federal Regulations. Title 21. Part 182 -- Substances Generally Recognized As Safe. Available at: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?CFRPart=182
  2. Khan A, Safdar M, Ali Khan M, et al. Cinnamon improves glucose and lipids of people with type 2 diabetes. Diabetes Care 2003;26:3215-8. PubMed
  3. De Benito V, Alzaga R. Occupational allergic contact dermatitis from cassia (Chinese cinnamon) as a flavouring agent in coffee. Contact Dermatitis 1999;40:165. PubMed
  4. Drake TE, Maibach HI. Allergic contact dermatitis and stomatitis caused by a cinnamic aldehyde-flavored toothpaste. Arch Dermatol 1976;112:202-3.
  5. Press release. Cinnamon capsules to reduce blood sugar are medicinal products! Efficacy has not been scientifically proven - some products contain high levels of coumarin. Federal Institute of Risk Assessment (BfM), Germany, November 11, 2006. Available a
  6. Felter SP, Vassallo JD, Carlton BD, Daston GP. A safety assessment of coumarin taking into account species-specificity of toxicokinetics. Food Chem Toxicol 2006;44:462-75. PubMed
  7. 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;22:507-12. PubMed
  8. Akilen, R., Tsiami, A., Devendra, D., and Robinson, N. Glycated haemoglobin and blood pressure-lowering effect of cinnamon in multi-ethnic Type 2 diabetic patients in the UK: a randomized, placebo-controlled, double-blind clinical trial. Diabet.Med. 2010; PubMed
  9. Lu T, Sheng H Wu J Cheng Y Zhu J Chen Y. Cinnamon extract improves fasting blood glucose and glycosylated hemoglobin level in Chinese patients with type 2 diabetes. Nutr Res. 2012;32(6):408-412. PubMed
  10. Choi, J., Lee, K. T., Ka, H., Jung, W. T., Jung, H. J., and Park, H. J. Constituents of the essential oil of the Cinnamomum cassia stem bark and the biological properties. Arch Pharm Res 2001;24(5):418-423.
  11. Altschuler JA, Casella SJ, MacKenzie TA, Curtis KM. The effect of cinnamon on A1C among adolescents with type 1 diabetes. Diabetes Care 2007;30(4):813-6. PubMed
  12. Stoecker BR, Zhan Z, Luo R, et al. Cinnamon extract lowers blood glucose in hyperglycemic subjects. FASEB J. 2010;22:722.1 (Abstract only). DOI
  13. Admani S, Hill H, Jacob SE. Cinnamon Sugar Scrub Dermatitis: "Natural" Is Not Always Best. Pediatr Dermatol. 2017;34(1):e42-e43. PubMed
  14. Isaac-Renton M, Li MK, Parsons LM. Cinnamon spice and everything not nice: many features of intraoral allergy to cinnamic aldehyde. Dermatitis. 2015;26(3):116-21. PubMed
  15. Vandersall A, Katta R. Eyelid dermatitis as a manifestation of systemic contact dermatitis to cinnamon. Dermatitis. 2015 Jul-Aug;26(4):189. PubMed
  16. Wickenberg J, Lindstedt S, Nilsson J, Hlebowicz J. Cassia cinnamon does not change the insulin sensitivity or the liver enzymes in subjects with impaired glucose tolerance. Nutr J 2014 Sep 24;13:96. PubMed
  17. Brancheau D, Patel B, Zughaib M. Do cinnamon supplements cause acute hepatitis? Am J Case Rep 2015;16:250-4. PubMed
  18. Shekarchizadeh-Esfahani P, Heydarpour F, Izadi F, Jalili C. The effect of cinnamon supplementation on liver enzymes in adults: A systematic review and meta-analysis of randomized controlled trials. Complement Ther Med 2021;58:102699. PubMed
  19. Bernaola J, Valverde-Monge M, Otal-Buesa M, Cullen D, Heras-Mendaza F. Cinnamon allergic contact cheilitis. Contact Dermatitis 2023;88(5):418-419. PubMed
  20. Patel K, Howard M, Tate B. Cheilitis caused by allergic contact dermatitis to cinnamon in chai tea: A case report. Contact Dermatitis 2023;88(3):239-240. PubMed

See these in context on the Cassia Cinnamon monograph →

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

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