Drug & supplement interaction

Ceylon Cinnamon + Metformin, Rosiglitazone

Metformin, Rosiglitazone brand name: Avandamet.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Ceylon Cinnamon has a moderate interaction with Metformin, Rosiglitazone. Theoretically, Ceylon cinnamon may have additive effects with antidiabetes drugs.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Ceylon Cinnamon and Metformin, Rosiglitazone

Here is the interaction we found between these two, with the evidence behind it.

Moderate

ANTIDIABETES DRUGS

Why this applies to Metformin, Rosiglitazone

Metformin, Rosiglitazone falls under ANTIDIABETES DRUGS — the group Ceylon Cinnamon interacts with.

Theoretically, Ceylon cinnamon may have additive effects with antidiabetes drugs.
Ceylon cinnamon may lower blood glucose levels. Dose adjustments might be necessary.
Severity Moderate Likelihood Possible Evidence D

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Avandamet pairs two diabetes medicines, metformin and rosiglitazone, that both work to bring your blood sugar down. The idea here is pretty simple: Ceylon cinnamon may nudge blood sugar a little lower on its own, so stacking it on top of these two could add up to more of a glucose-lowering effect.

In real life, that mostly matters if your sugar drifts too low. Watch for the usual signs like shakiness, sweating, dizziness, or feeling foggy. I'll be honest though, the evidence for this is weak and based on lab and animal studies, so a sprinkle on your oatmeal is very unlikely to cause trouble. Concentrated capsules are a different story. If you're considering those, check with your pharmacist or doctor first so any dose can be watched.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Anderson RA, Broadhurst CL, Polansky MM, et al. Isolation and Characterization of Polyphenol Type-A Polymers from Cinnamon with Insulin-like Biological Activity. J Agric Food Chem 2004;52:65-70. PubMed
  2. Jarvill-Taylor KJ, Anderson RA, Graves DJ. A hydroxychalcone derived from cinnamon functions as a mimetic for insulin in 3T3-L1 adipocytes. J Am Coll Nutr 2001;20:327-36. PubMed
  3. Onderoglu S, Sozer S, Erbil KM, et al. The evaluation of long-term effcts of cinnamon bark and olive leaf on toxicity induced by streptozotocin administration to rats. J Pharm Pharmacol 1999;51:1305-12.

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Ceylon Cinnamon Also Interacts With Other Medications

Ceylon Cinnamon has 257 moderate known drug interactions in our database — the Metformin, Rosiglitazone one above is one of them. If you take anything else, check it against the full list below.

Moderate 257 No known interaction 2,573 (incl. Metformin, Rosiglitazone)
Taking anything else?

Check Another of Your Medications Against Ceylon Cinnamon

Covers the 2,830 medications we’ve checked against Ceylon Cinnamon. Pick one to open its full report.

From our Q&A

Questions About Ceylon Cinnamon or Metformin, Rosiglitazone

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Ceylon Cinnamon or Metformin, Rosiglitazone, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Metformin, Rosiglitazone

This page covers Ceylon Cinnamon only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Metformin, Rosiglitazone page lists 315 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Beer (major), Siberian Cocklebur (major), Wine (major) and Acai (moderate).

By severity: 4 major · 268 moderate · 43 minor.

From our pharmacist’s overview on the Metformin, Rosiglitazone page

“Avandamet pairs metformin with rosiglitazone to manage type 2 diabetes, and its supplement list calls for genuine care rather than a quick skim. Start with the four major-rated entries: alcohol and the herb Siberian cocklebur can each stress the liver, a serious concern with rosiglitazone on board, while activated charcoal can soak up…”

Reviewed by 2 · Jul 18, 2026

Open the Metformin, Rosiglitazone interaction page

One more smart check

Taking Ceylon Cinnamon as Part of a Dietary Supplement Product? Check It for Interactions

We hold 362 real supplement products containing Ceylon Cinnamon, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Ceylon Cinnamon. Your product may carry other ingredients that interact with Metformin, Rosiglitazone too, on top of Ceylon Cinnamon — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Ceylon Cinnamon and Metformin, Rosiglitazone Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Ceylon Cinnamon
Top 25%

#338 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Metformin, Rosiglitazone
Steady interest

#1,748 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Supplement

About Ceylon Cinnamon

What is Ceylon Cinnamon?

Ceylon Cinnamon
  • Blood sugar support
  • High cholesterol
  • Indigestion and gas
  • Antimicrobial
  • General flavoring and culinary use

Ceylon cinnamon is the so-called 'true' cinnamon, valued as a spice and used in traditional medicine for blood sugar, cholesterol, and digestion. Evidence for most health benefits is limited and mixed, but as a food it is generally safe and contains far less coumarin than common cassia cinnamon. Talk with your pharmacist or doctor before taking concentrated supplements, especially if you have a health condition or take medications.

Read the full Ceylon Cinnamon monograph & all interactions
Keep checking

Other Drugs & Ceylon Cinnamon

Browse every other medication we’ve checked against Ceylon Cinnamon — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
257Moderate
0Minor
2,572No known interaction
257 Moderate 2,572 No interaction
Moderate

257 interactions

Showing 60 of 257 moderate interactions — see all 257 on the Ceylon Cinnamon page.

No interaction 2,572 drugs checked — show the list

We also checked Ceylon Cinnamon against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,572 medications checked with no known interaction — see the full Ceylon Cinnamon list.

See the full Ceylon Cinnamon interactions page
See every supplement checked against Metformin, Rosiglitazone, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

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

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

Keep exploring
Ceylon Cinnamon monograph › Uses, safety, and every drug interaction in one place Metformin, Rosiglitazone supplement interactions › Every supplement checked against Metformin, Rosiglitazone, ranked by severity Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Ceylon Cinnamon and Metformin, Rosiglitazone Together: Common Questions

Can you take Ceylon Cinnamon with Metformin, Rosiglitazone?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Ceylon Cinnamon and Metformin, Rosiglitazone interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

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

Still Have a Question About Metformin, Rosiglitazone and Ceylon Cinnamon?

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.