Drug & supplement interaction

Ceylon Cinnamon + Cephalexin

Cephalexin brand names: Keflex, Keftab, Cephalex, Lexin.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Ceylon Cinnamon and Cephalexin in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Ceylon Cinnamon and Cephalexin

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Cephalexin and Ceylon Cinnamon in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Ceylon Cinnamon safety at a glance

Ceylon Cinnamon overall Use caution Generally safe as a food spice, but supplement-strength doses are less studied.
Pregnancy Likely Safe When consumed in amounts commonly found in foods. Read the full pregnancy detail
Breastfeeding Likely Safe When consumed in amounts commonly found in foods. There is insufficient reliable information available about the safety of Ceylon cinnamon in amounts greater th... Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Cephalexin and Ceylon Cinnamon? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Cephalexin

Interactions in our licensed database are recorded against drug classes, not just single drug names. Cephalexin is filed under 7 classifications — including organic anion transporter 3 (oat3) substrates, organic anion transporter 1 (oat1) substrates, antibiotic drugs. Ceylon Cinnamon has documented interactions with 2 drug classes — the most serious being antidiabetes drugs (moderate) and antihypertensive drugs (moderate) — and none of Cephalexin’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Ceylon Cinnamon Does Interact With Other Medications

Ceylon Cinnamon has 258 moderate known drug interactions in our database — Cephalexin isn’t one of them. If you take anything else, check it against the full list below.

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.

What to actually watch for

No Interaction Found — But Data Suggests Ceylon Cinnamon and Cephalexin May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do. 2 of them are worth acting on rather than waiting out — marked below.

  • Liver problems Worth acting on Additional detail

    Ceylon Cinnamon

    “While there is concern about the coumarin content in cassia cinnamon increasing the risk for hepatic adverse effects and bleeding, the amount of coumarin in Ceylon cinnamon is negligible and unlikely to cause toxic effects.”

    Ceylon Cinnamon · Natural Medicines adverse-effect record, reported in hepatitis.

    4 sources cited
    1. 89652. Ranasinghe P, Jayawardena R, Galappaththy P, et al. Response to Akilen et al. Efficacy and safety of 'true' cinnamon (Cinnamomum zeylanicum) as a pharmaceutical agent in diabetes: a systematic review and meta-analysis. Diabet Med 2013 Apr;30(4):506-7.
    2. 92072. Ranasinghe P, Pigera S, Premakumara GA, et al. Medicinal properties of 'true' cinnamon (Cinnamomum zeylanicum): a systematic review. BMC Complement Altern Med 2013;13:275. PubMed
    3. 92073. Ranasinghe P, Galappaththy P. Health benefits of Ceylon cinnamon (Cinnamomum zeylanicum): a summary of the current evidence. Ceylon Med J 2016;61(1):1-5. PubMed
    4. 97249. Brancheau D, Patel B, Zughaib M. Do cinnamon supplements cause acute hepatitis? Am J Case Rep 2015;16:250-4. PubMed

    Cephalexin

    Listed in the ADVERSE REACTIONS section of the FDA label for Cephalexin. Read the label on DailyMed ›

  • Bleeding or bruising Worth acting on Additional detail

    Ceylon Cinnamon

    “Orally, a case of postoperative hemorrhage is reported in a 49-year-old patient after taking Ceylon cinnamon 1 tablespoon daily for 10 months. One day post-colectomy, the patient had an INR of 1.59 and intraabdominal bleeding that required exploratory laparotomies, blood transfusion, and fresh frozen plasma. Ultimately, the patient was discharged.”

    Ceylon Cinnamon · Natural Medicines adverse-effect record, reported in bleeding.

    1 source cited
    1. 112421. Chase C, Doyle A, John SS, Laurent T, Griffith S. Post-operative haemorrhage secondary to cinnamon use. A case report. Int J Surg Case Rep 2022;95:107179. PubMed

    Cephalexin

    Listed in the ADVERSE REACTIONS section of the FDA label for Cephalexin. Read the label on DailyMed ›

  • Stomach upset / Nausea Additional detail

    Ceylon Cinnamon

    “Orally, gastrointestinal side effects such as heartburn, nausea, bloating, and dyspepsia have been reported.”

    Ceylon Cinnamon · Natural Medicines adverse-effect record, reported in dyspepsia.

    1 source cited
    1. 97250. Ranasinghe P, Jayawardena R, Pigera S, et al. Evaluation of pharmacodynamic properties and safety of Cinnamomum zeylanicum (Ceylon cinnamon) in healthy adults: a phase I clinical trial. BMC Complement Altern Med 2017;17(1):550. PubMed

    Cephalexin

    Listed in the ADVERSE REACTIONS section of the FDA label for Cephalexin. Read the label on DailyMed ›

  • Itching Additional detail

    Ceylon Cinnamon

    “Orally, a case of systemic contact dermatitis has been reported in a patient who consumed cinnamon (type not specified) after being previously sensitized to cinnamyl alcohol via cutaneous exposure. In a small study of oral Ceylon cinnamon, two patients reported itching.”

    Ceylon Cinnamon · Natural Medicines adverse-effect record, reported in dermatitis.

    6 sources cited
    1. 95599. Vandersall A, Katta R. Eyelid dermatitis as a manifestation of systemic contact dermatitis to cinnamon. Dermatitis. 2015 Jul-Aug;26(4):189. PubMed
    2. 104520. Zareie A, Sahebkar A, Khorvash F, Bagherniya M, Hasanzadeh A, Askari G. Effect of cinnamon on migraine attacks and inflammatory markers: A randomized double-blind placebo-controlled trial. Phytother Res 2020;34(11):2945-52. PubMed
    3. 108263. Zobeiri M, Parvizi F, Shahpiri Z, et al. Evaluation of the effectiveness of cinnamon oil soft capsule in patients with functional dyspepsia: A randomized double-blind placebo-controlled clinical trial. Evid Based Complement Alternat Med 2021;2021:6634115. PubMed
    4. 2537. Choi HK, Jung GW, Moon KH, et al. Clinical study of SS-Cream in patients with lifelong premature ejaculation. Urology 2000;55:257-61. PubMed
    5. 12635. Kanerva L, Estlander T, Jolanki R. Occupational allergic contact dermatitis from spices. Contact Dermatitis 1996;35:157-62. PubMed
    6. 92071. Oliveira JdA, da Silva IC, Trindade LA, et al. Safety and tolerability of essential oil from Cinnamomum zeylanicum blume leaves with action on oral candidosis and its effect on the physical properties of the acylic resin. Evid Based Complement Alternat Me

    Cephalexin

    Listed in the ADVERSE REACTIONS section of the FDA label for Cephalexin. Read the label on DailyMed ›

  • Stomach pain / Vomiting Additional detail

    Ceylon Cinnamon

    Recorded for Ceylon Cinnamon in the same Natural Medicines adverse-effect record shown under Liver problems above.

    Cephalexin

    Listed in the ADVERSE REACTIONS section of the FDA label for Cephalexin. Read the label on DailyMed ›

Reported for Ceylon Cinnamon but not commonly for Cephalexin: a skin rash, heartburn and bloating or gas.

Effects for Cephalexin come from the ADVERSE REACTIONS section of its FDA label; effects for Ceylon Cinnamon come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Ceylon Cinnamon in Pregnancy & Breastfeeding

Pregnancy Likely Safe

When consumed in amounts commonly found in foods.

Pregnancy Likely Unsafe

When used orally in amounts greater than those found in foods. Fetal abnormalities have been reported in animals.

Lactation Likely Safe

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

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

From our Q&A

Questions About Ceylon Cinnamon or Cephalexin

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 Cephalexin, 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 Cephalexin

This page covers Ceylon Cinnamon only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Cephalexin page lists 61 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Asarabacca (major), Siberian Cocklebur (major), African Wild Potato (moderate) and Aristolochia (moderate).

By severity: 3 major · 47 moderate · 11 minor.

From our pharmacist’s overview on the Cephalexin page

“Cephalexin (Keflex) is one of the most commonly prescribed oral antibiotics, usually for skin and urinary infections, and its supplement list warrants genuine care rather than a quick skim. Three of the 61 ingredients on file rate major.”

Reviewed by 2 · Jul 18, 2026

Open the Cephalexin 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. Even though Ceylon Cinnamon itself has no known interaction with Cephalexin, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Ceylon Cinnamon and Cephalexin 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%

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

29 days ago today
Medication Cephalexin
Top 5%

#69 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.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Ceylon Cinnamon reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Ceylon Cinnamon and Cephalexin records this page draws on were last updated July 11, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
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.

Cinnamomum verum · Lauraceae · Inner bark (and bark-derived essential oil) · Ground spice, capsules, powder, extracts, tea, essential oil

An interaction check asks whether these two react with each other — it does not ask whether Ceylon Cinnamon is a good idea for someone in your situation. Here is what our Ceylon Cinnamon record says about it on its own.

Ceylon Cinnamon: dosing

There is no official, standardized dose of Ceylon cinnamon for any health condition. Amounts used in studies have varied widely, and many studies used cassia cinnamon, so results may not apply to Ceylon products.If you choose to take a supplement, follow the directions on the product label and do not exceed the recommended amount.

From our Ceylon Cinnamon monograph — the full record covers uses, side effects and every documented interaction.

Read the full Ceylon Cinnamon monograph & all interactions
Medication

About Cephalexin

What Is Cephalexin Used For?

Brand names: Keflex, Keftab, Cephalex, Lexin

Cephalexin treats bacterial infections caused by susceptible strains of bacteria. It is used for respiratory tract infections, ear infections (otitis media), skin and skin structure infections, bone infections, and genitourinary tract infections — including acute prostatitis.

It works only against bacterial infections — not viruses like colds or flu. Your prescriber should use it only when a bacterial infection is confirmed or strongly suspected, to help prevent antibiotic resistance.

Most-Reported Side Effects for Cephalexin

From FAERS, the FDA’s public side-effect reporting system (0 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Chronic kidney disease 2,157 reports
Renal failure 1,558 reports
Acute kidney injury 1,550 reports
Diarrhea 1,405 reports
Fatigue 1,303 reports
See full Cephalexin drug information
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
258Moderate
0Minor
2,571No known interaction
Moderate

258 interactions

Showing 60 of 258 moderate interactions — see all 258 on the Ceylon Cinnamon page.

No interaction 2,571 drugs checked — show the list
Evidence & sources

Ceylon Cinnamon References

The 22 references that drive our Ceylon Cinnamon monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
  2. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
  3. Choi HK, Jung GW, Moon KH, et al. Clinical study of SS-Cream in patients with lifelong premature ejaculation. Urology 2000;55:257-61. PubMed
  4. 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
  5. 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
  6. 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
  7. 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.
  8. Kanerva L, Estlander T, Jolanki R. Occupational allergic contact dermatitis from spices. Contact Dermatitis 1996;35:157-62. PubMed
  9. Ranasinghe P, Jayawardena R, Galappaththy P, et al. Response to Akilen et al. Efficacy and safety of 'true' cinnamon (Cinnamomum zeylanicum) as a pharmaceutical agent in diabetes: a systematic review and meta-analysis. Diabet Med 2013 Apr;30(4):506-7.
  10. Oliveira JdA, da Silva IC, Trindade LA, et al. Safety and tolerability of essential oil from Cinnamomum zeylanicum blume leaves with action on oral candidosis and its effect on the physical properties of the acylic resin. Evid Based Complement Alternat Me
  11. Ranasinghe P, Pigera S, Premakumara GA, et al. Medicinal properties of 'true' cinnamon (Cinnamomum zeylanicum): a systematic review. BMC Complement Altern Med 2013;13:275. PubMed
  12. Ranasinghe P, Galappaththy P. Health benefits of Ceylon cinnamon (Cinnamomum zeylanicum): a summary of the current evidence. Ceylon Med J 2016;61(1):1-5. PubMed
  13. Nyadjeu P, Dongmo A, Nguelefack TB, Kamanyi A. Antihypertensive and vasorelaxant effects of Cinnamomum zeylanicum stem bark aqueous extracts. J Complement Integr Med 2011;8.
  14. Wansi SL, Nyadjeu P, Ngamga D, et al. Blood pressure lowering effect of the ethanol extract from the stembark of Cinnamomum zeylanicum (lauraceae) in rats. Pharmacol online 2007;3:166-76.
  15. Admani S, Hill H, Jacob SE. Cinnamon Sugar Scrub Dermatitis: "Natural" Is Not Always Best. Pediatr Dermatol. 2017;34(1):e42-e43. PubMed

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Ceylon Cinnamon and Cephalexin Together: Common Questions

Is it safe to take Ceylon Cinnamon with Cephalexin?
We do not list a known interaction between Ceylon Cinnamon and Cephalexin. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Do Ceylon Cinnamon and Cephalexin have any of the same side effects?
Yes — our sources link each of them separately to 7 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
How was the Ceylon Cinnamon and Cephalexin combination checked?
Interactions in our licensed database are recorded against drug classes. Cephalexin is filed under 7 classifications, and Ceylon Cinnamon has documented interactions with 2 drug classes — none of Cephalexin's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Ceylon Cinnamon interact with any other medications?
Yes. Ceylon Cinnamon has 258 documented drug interactions in our database — Cephalexin is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Cephalexin interact with any supplements?
Yes. Cephalexin has documented interactions with 61 supplements in our database — Ceylon Cinnamon is not one of them. The Cephalexin interaction page linked on this page lists every one, ranked by severity.

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

Still Have a Question About Cephalexin 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.