Herb & supplement monograph

Ceylon Cinnamon Drug Interactions, Uses, Effectiveness, Safety & More

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS ·Updated July 2026

What is this page for?

First and foremost: how Ceylon Cinnamon interacts with medications. The heart of this page is the interaction list — every drug Ceylon Cinnamon is known to interact with, and how serious each one is.

But these pages have grown well beyond that into a full monograph — what Ceylon Cinnamon is, what people use it for and how strong the evidence is, its safety and side effects, and answers to the questions we’re asked most — written and reviewed by the clinical staff at HelloPharmacist. It’s educational information from our licensed clinical databases, not medical advice, and we don’t sell or endorse products. Our editorial policy

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Ceylon Cinnamon Drug Interactions: The Bottom Line

From the HelloPharmacist Editorial Team · Updated July 2026

Based on the available evidence, the overall risk of a clinically significant Ceylon Cinnamon drug interaction appears low for most people. None of the listed interactions are rated major, and every one rests on theoretical or animal research rather than solid human studies.

Interactions deserving the most attention

The combinations that deserve the most care involve diabetes medications and blood pressure medications. Ceylon cinnamon may lower blood glucose on its own, so pairing it with drugs that do the same could, in theory, push blood sugar too low. Animal studies also show it can relax blood vessels and reduce blood pressure, which might add to the effect of blood pressure treatments. Because both blood sugar and blood pressure are closely watched numbers, even a modest added effect is worth knowing about.

What the rest of the list means

Although the list of interacting medications is long, it really reflects just two broad drug groups, and every entry within them is graded as possible only. That means the concerns come from lab and animal findings or theory, not from proven problems in people. A long list here signals caution and awareness, not established harm from each combination.

Check your medications against Ceylon Cinnamon

Based on HelloPharmacist’s Ceylon Cinnamon interaction data and reviewed under our editorial standards.

Interaction report

Drugs that interact with Ceylon Cinnamon

258 medications have a known interaction with Ceylon Cinnamon, graded by severity. Select any drug for the full evidence-based detail.

Don’t want to scroll the list? Just ask.

Tell us the medications you take and we’ll check each one against Ceylon Cinnamon using our pharmacist-reviewed interaction data.

AI summaries are generated from our Ceylon Cinnamon interaction data for education only — always confirm with your pharmacist. How we use AI

2,830 drugs

Read The List Like a Pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
Probable. Interaction 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.
Possible. 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
Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
Each drug listed above links to the full report for that exact Ceylon Cinnamon combination — clinical detail, likelihood, evidence level, and citations.
Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

The big picture

The kinds of drugs Ceylon Cinnamon affects

Every type of medication (drug category) Ceylon Cinnamon is known to interact with. Open any category for the detail — or search your exact drug in the checker above.

All 2 drug categories Ceylon Cinnamon interacts with

Antidiabetes DrugsAntihypertensive Drugs

Antidiabetes Drugs

Theoretically, Ceylon cinnamon may have additive effects with antidiabetes drugs.
Ceylon cinnamon may lower blood glucose levels. Dose adjustments might be necessary.

Likelihood Possible Evidence D

Antihypertensive Drugs

Theoretically, Ceylon cinnamon might have additive effects with antihypertensive drugs and increase the risk of hypotension.
Animal research shows that Ceylon cinnamon extract has vasorelaxant properties and reduces blood pressure in rat models of hypertension, possibly via inhibition of calcium influx through L-type voltage-sensitive channels.

Likelihood Possible Evidence D

Monograph

Ceylon Cinnamon: Uses, Safety & Side Effects

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Reviewed July 2026 ·

The bottom line

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.

Scientific name: Cinnamomum verum
Family: Lauraceae
Part used: Inner bark (and bark-derived essential oil)
Common forms: Ground spice, capsules, powder, extracts, tea, essential oil

People commonly use it for

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

Popular and traditional uses — not proof it works. See “Uses & effectiveness” below for the evidence.

Safety at a glance

OverallUse caution

Generally safe as a food spice, but supplement-strength doses are less studied.

PregnancyLikely Safe

When consumed in amounts commonly found in foods.

Read the full pregnancy detail

BreastfeedingLikely Safe

When consumed in amounts commonly found in foods. There is insufficient reliable information available about the safety of Ceylon cinnamon in amounts...

Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center). Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

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Overview

Ceylon cinnamon comes from the inner bark of the Cinnamomum verum tree, which is native to Sri Lanka and also grown in other parts of South Asia. It is often called 'true' cinnamon to set it apart from the more common and cheaper cassia cinnamon found in many grocery stores. Ceylon cinnamon has a lighter color, a softer, crumbly texture, and a milder, sweeter taste.

People use Ceylon cinnamon mainly as a cooking and baking spice. The bark is also used in traditional medicine and is sold as capsules, powders, extracts, and teas. A key reason some people prefer Ceylon cinnamon over cassia is that it naturally contains much less coumarin, a compound that can be harmful to the liver in large amounts.

How it works

Cinnamon contains several active compounds, the best known being cinnamaldehyde, which gives the spice its smell and flavor. It also contains antioxidants called polyphenols.

Laboratory and animal research suggests these compounds may help cells respond better to insulin, slow how quickly carbohydrates are broken down in the gut, and reduce inflammation and oxidative stress. Cinnamaldehyde and cinnamon oil also show antimicrobial activity against some bacteria and fungi in test-tube studies.

It is important to know that these mechanisms are mostly based on lab and animal work. Effects seen in a test tube do not always translate into meaningful benefits in people.

Effectiveness

Does Ceylon Cinnamon work?

Here’s what the research actually shows for each use — graded by Natural Medicines and reviewed by Dr. Brian Staiger, PharmD.

Evidence overview · 20 uses evaluated

2 Leans ineffective 18 Insufficient evidence

How to read these evidence grades

Natural Medicines’ 7-point scale. We show each rating’s label word-for-word.

1EffectiveStrong, consistent evidence it works.

2Likely EffectiveGood evidence, though not yet conclusive.

3Possibly EffectiveSome evidence suggests a benefit.

4Possibly IneffectiveSome evidence it may not help.

5Likely IneffectiveFairly strong evidence it doesn’t help.

6IneffectiveStrong evidence it doesn’t work.

7Insufficient Reliable Evidence to RateToo little research to say either way.

Possibly Ineffective Diabetes