Drug & supplement interaction

Onion + Rosiglitazone Maleate

Rosiglitazone Maleate brand name: Avandia.

Moderate Interaction
The bottom line Moderate

Onion has a moderate interaction with Rosiglitazone Maleate. Concomitant use of antidiabetes drugs with onion may increase the risk of hypoglycemia.

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

Onion and Rosiglitazone Maleate

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

Moderate

ANTIDIABETES DRUGS

Why this applies to Rosiglitazone Maleate

Rosiglitazone Maleate falls under ANTIDIABETES DRUGS — the group Onion interacts with.

Concomitant use of antidiabetes drugs with onion may increase the risk of hypoglycemia.
Animal research and clinical research shows that taking onion can lower blood glucose levels. Monitor blood glucose levels closely.
Severity Moderate Likelihood Possible Evidence B

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

Here's the simple version: onion seems to have a mild blood sugar lowering effect of its own, and you're already taking rosiglitazone (Avandia) to bring your sugar down. Stack the two together and your numbers could dip lower than you expect. This isn't onion changing how your body processes the drug, it's more that both are nudging your blood sugar in the same downward direction.

If your sugar drops too low, you might feel shaky, sweaty, lightheaded, hungry, or just off. The good news is this is based on lower quality studies, and normal cooking amounts of onion in your meals are very unlikely to cause trouble. It's the concentrated onion supplements that are worth a second thought. If you want to use those, check your sugars a bit more closely and chat with your pharmacist or doctor first.

References
  1. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  2. Mathew, P. T. and Augusti, K. T. Hypoglycaemic effects of onion, Allium cepa Linn. on diabetes mellitus - a preliminary report. Indian J.Physiol Pharmacol. 1975;19(4):213-217.
  3. Campos, K. E., Diniz, Y. S., Cataneo, A. C., Faine, L. A., Alves, M. J., and Novelli, E. L. Hypoglycaemic and antioxidant effects of onion, Allium cepa: dietary onion addition, antioxidant activity and hypoglycaemic effects on diabetic rats. Int J Food S
  4. El Demerdash, F. M., Yousef, M. I., and El Naga, N. I. Biochemical study on the hypoglycemic effects of onion and garlic in alloxan-induced diabetic rats. Food Chem.Toxicol. 2005;43(1):57-63. PubMed
  5. Kook, S., Kim, G. H., and Choi, K. The antidiabetic effect of onion and garlic in experimental diabetic rats: meta-analysis. J Med Food 2009;12(3):552-560. PubMed
  6. Sharma, K. K., Gupta, R. K., Gupta, S., and Samuel, K. C. Antihyperglycemic effect of onion: effect on fasting blood sugar and induced hyperglycemia in man. Indian J.Med.Res. 1977;65(3):422-429.
  7. Jain, R. C., Vyas, C. R., and Mahatma, O. P. Letter: Hypoglycaemic action of onion and garlic. Lancet 12-29-1973;2(7844):1491.
  8. Jain, R. C. and Vyas, C. R. Letter: Hypoglycaemia action of onion on rabbits. Br.Med.J. 6-29-1974;2(5921):730. PubMed
  9. Tjokroprawiro, A., Pikir, B. S., Budhiarta, A. A., Pranawa, Soewondo, H., Donosepoetro, M., Budhianto, F. X., Wibowo, J. A., Tanuwidjaja, S. J., Pangemanan, M., and . Metabolic effects of onion and green beans on diabetic patients. Tohoku J Exp Med 1983; PubMed
  10. Akash MS, Rehman K, Chen S. Spice plant Allium cepa: dietary supplement for treatment of type 2 diabetes mellitus. Nutrition 2014;30(10):1128-37. PubMed
  11. Eldin IM, Ahmed EM, HM AE. Preliminary study of the clinical hypoglycemic effects of Allium cepa (red onion) in type 1 and type 2 diabetic patients. Environmental health insights 2010;4:71. PubMed

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

Onion Also Interacts With Other Medications

Onion has 274 moderate known drug interactions in our database — the Rosiglitazone Maleate one above is one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Onion

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

Everything else you take

See Every Supplement That Interacts With Rosiglitazone Maleate

This page covers Onion only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Rosiglitazone Maleate page lists 314 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 · 266 moderate · 44 minor.

From our pharmacist’s overview on the Rosiglitazone Maleate page

“Rosiglitazone (Avandia) lowers blood sugar in type 2 diabetes, and most of the 314 supplements and herbs on this page pull on that same lever. Some 239 can move blood glucose on their own, so adding one risks hypoglycemia, the shakiness, sweating, and confusion of sugar falling too low.”

Reviewed by 2 · Jul 18, 2026

Open the Rosiglitazone Maleate interaction page

One more smart check

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

We hold 1,061 real supplement products containing Onion, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Onion. Your product may carry other ingredients that interact with Rosiglitazone Maleate too, on top of Onion — 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 Onion and Rosiglitazone Maleate 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 Onion
Top 25%

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

29 days ago today
Medication Rosiglitazone Maleate
Top 5%

#141 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 Onion

What is Onion?

Onion
  • Colds and respiratory symptoms
  • Heart and cholesterol health
  • Blood sugar support
  • Antimicrobial and wound care
  • Scar appearance (topical gels)

Onion is a common food with a long history in traditional medicine, and it contains antioxidants like quercetin and sulfur compounds. Eating onion as part of a balanced diet is safe for most people, but high-dose supplements have only limited human evidence for any specific health condition. Talk with your pharmacist or doctor before using concentrated onion products for a medical reason.

Read the full Onion monograph & all interactions
Medication

About Rosiglitazone

What Is Rosiglitazone Used For?

Brand name: Avandia

  • Rosiglitazone is used along with a diet and exercise program and sometimes with one or more other medications to treat type 2 diabetes (condition in which the body does not use insulin normally and therefore cannot control the amount of sugar in the blood). Rosiglitazone is in a class of medications called thiazolidinediones. It works by increasing the body's sensitivity to insulin, a natural substance that helps control blood sugar levels. Rosiglitazone is not used to treat type 1 diabetes (condition in which the body does not produce insulin and therefore cannot control the amount of sugar in the blood) or diabetic ketoacidosis (a serious condition that may occur if high blood sugar is not treated).

  • Over time, people who have diabetes and high blood sugar can develop serious or life-threatening complications, including heart disease, stroke, kidney problems, nerve damage, and eye problems. Taking medication(s), making lifestyle changes (e.g., diet, exercise, quitting smoking), and regularly checking your blood sugar may help to manage your diabetes and improve your health. This therapy may also decrease your chances of having a heart attack, stroke, or other diabetes-related complications such as kidney failure, nerve damage (numb, cold legs or feet; decreased sexual ability in men and women), eye problems, including changes or loss of vision, or gum disease. Your doctor and other healthcare providers will talk to you about the best way to manage your diabetes.

See full Rosiglitazone drug information
Keep checking

Other Drugs & Onion

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

0Major
274Moderate
0Minor
2,555No known interaction
Moderate

274 interactions

Showing 60 of 274 moderate interactions — see all 274 on the Onion page.

No interaction 2,555 drugs checked — show the list
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

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Pharmacist Counseling Corner

Taking Onion and Rosiglitazone Maleate Together: Common Questions

Can you take Onion with Rosiglitazone Maleate?
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 Onion and Rosiglitazone Maleate 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 Rosiglitazone Maleate and Onion?

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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.