Drug & supplement interaction

Flaxseed + Glyburide, Metformin

Glyburide, Metformin brand name: Glucovance.

Moderate Interaction
The bottom line Moderate

Flaxseed has a moderate interaction with Glyburide, Metformin. Theoretically, flaxseed might have additive effects when used with antidiabetes drugs and increase the risk for hypoglycemia.

Read the full interaction report
SeverityModerate
LikelihoodProbable
EvidenceB
What do Severity, Likelihood & Evidence mean?
Know someone taking this? Share
Interaction report

Flaxseed and Glyburide, Metformin

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

Moderate

ANTIDIABETES DRUGS

Why this applies to Glyburide, Metformin

Glyburide, Metformin falls under ANTIDIABETES DRUGS — the group Flaxseed interacts with.

Theoretically, flaxseed might have additive effects when used with antidiabetes drugs and increase the risk for hypoglycemia.
Some clinical research suggests that flaxseed can lower blood glucose levels.
Severity Moderate Likelihood Probable Evidence B

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..

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

Glucovance combines two diabetes medicines, glyburide and metformin, that both work to bring your blood sugar down. Here's the thing about flaxseed: some studies suggest it can gently lower blood sugar on its own. So when you stack flaxseed on top of your medication, the two can add together and push your numbers lower than you intended.

This isn't a dangerous chemical clash, just an additive effect, and the evidence is fairly modest. Still, glyburide especially can cause low blood sugar, so watch for shakiness, sweating, dizziness, or confusion. Eating flaxseed sprinkled on food is unlikely to cause trouble, but concentrated supplement doses are worth a conversation. Keep checking your sugars and let your pharmacist or doctor know before adding a flaxseed supplement.

References
  1. Cunnane SC, Ganguli S, Menard C, et al. High alpha-linolenic acid flaxseed (Linum usitatissimum): some nutritional properties in humans. Br J Nutr 1993;69:443-53.
  2. Lemay A, Dodin S, Kadri N, et al. Flaxseed dietary supplement versus hormone replacement therapy in hypercholesterolemic menopausal women. Obstet Gynecol 2002;100:495-504.. DOI
  3. Mani UV, Mani I, Biswas M, Kumar SN. An open-label study on the effect of flax seed powder (Linum usitatissimum) supplementation in the management of diabetes mellitus. J Diet Suppl 2011;8:257-65.
  4. Rhee Y, Brunt A. Flaxseed supplementation improved insulin resistance in obese glucose intolerant people: a randomized crossover design. Nutr J 2011;10:44. PubMed
  5. Villarreal-Renteria AI, Herrera-Echauri DD, Rodríguez-Rocha NP, et al. Effect of flaxseed (Linum usitatissimum) supplementation on glycemic control and insulin resistance in prediabetes and type 2 diabetes: A systematic review and meta-analysis of randomi

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

Flaxseed Also Interacts With Other Medications

Flaxseed has 596 moderate known drug interactions in our database — the Glyburide, Metformin 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 Flaxseed

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

From our Q&A

Questions About Flaxseed or Glyburide, Metformin

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Flaxseed or Glyburide, Metformin, 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 Glyburide, Metformin

This page covers Flaxseed only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Glyburide, Metformin page lists 332 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Apple (major), Beer (major), Grapefruit (major) and Siberian Cocklebur (major).

By severity: 7 major · 281 moderate · 44 minor.

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

“Glucovance combines glyburide and metformin to lower blood sugar, and its list of 332 interacting supplements deserves real care, starting with the seven rated major. Most entries, 239 of them, lower blood sugar on their own, so stacking one on top of a drug built to do exactly that can drop your glucose into dangerous territory.”

Reviewed by 2 · Jul 18, 2026

Open the Glyburide, Metformin interaction page

One more smart check

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

We hold 236 real supplement products containing Flaxseed, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Flaxseed. Your product may carry other ingredients that interact with Glyburide, Metformin too, on top of Flaxseed — 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 Flaxseed and Glyburide, Metformin 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 Flaxseed
Top half

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

29 days ago today
Medication Glyburide, Metformin
Steady interest

#1,595 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 Flaxseed

What is Flaxseed?

Flaxseed
  • Constipation and digestive health
  • High cholesterol
  • Heart health
  • Menopausal symptoms
  • Blood sugar support

Flaxseed is a nutritious food rich in fiber, omega-3 fats (ALA), and plant compounds called lignans. It is most reliably helpful for constipation and may modestly lower cholesterol, but evidence for many other uses is mixed or limited. It is generally safe as a food, but talk to your pharmacist or doctor before using it as a supplement, especially if you are pregnant or breastfeeding.

Read the full Flaxseed monograph & all interactions
Keep checking

Other Drugs & Flaxseed

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

0Major
596Moderate
0Minor
2,233No known interaction
Moderate

596 interactions

Showing 60 of 596 moderate interactions — see all 596 on the Flaxseed page.

No interaction 2,233 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

Keep exploring
Pharmacist Counseling Corner

Taking Flaxseed and Glyburide, Metformin Together: Common Questions

Can you take Flaxseed with Glyburide, Metformin?
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 Flaxseed and Glyburide, Metformin 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 Glyburide, Metformin and Flaxseed?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.