Drug & supplement interaction

Agaricus Mushroom + Metformin Hydrochloride

Metformin Hydrochloride brand name: Riomet ER.

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

Agaricus Mushroom has a moderate interaction with Metformin Hydrochloride. Theoretically, taking agaricus mushroom with antidiabetes drugs might increase the risk of hypoglycemia.

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

Agaricus Mushroom and Metformin Hydrochloride

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

Moderate

ANTIDIABETES DRUGS

Why this applies to Metformin Hydrochloride

Metformin Hydrochloride falls under ANTIDIABETES DRUGS — the group Agaricus Mushroom interacts with.

Theoretically, taking agaricus mushroom with antidiabetes drugs might increase the risk of hypoglycemia.
In one clinical study in patients with type 2 diabetes who are stabilized on conventional oral hypoglycemic agents, 3 of 29 patients taking an agaricus mushroom extract 500 mg three times daily for 12 weeks reported hypoglycemia, compared to one of 29 patients in the placebo group.
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

Here's the gist for you: agaricus mushroom may have a mild blood sugar lowering effect of its own. When you stack that on top of metformin, the two could add up and push your glucose lower than you'd want. This isn't about the mushroom changing how your body breaks down metformin, it's simply two things nudging sugar in the same direction.

I want to be honest about how thin the evidence is. This is mostly a theoretical concern from pharmacology, and in one small study only a few people on the extract reported low sugar. Metformin alone rarely causes true hypoglycemia, but watch for shakiness, sweating, dizziness, or feeling foggy, especially if you also take other diabetes meds. Chat with your pharmacist or doctor before adding it.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Hsu CH, Liao YL, Lin SC, et al. The mushroom Agaricus Blazei Murill in combination with metformin and gliclazide improves insulin resistance in type 2 diabetes: a randomized, double-blinded, and placebo-controlled clinical trial. J Altern Complement Med 2

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

Agaricus Mushroom Also Interacts With Other Medications

Agaricus Mushroom has 85 moderate known drug interactions in our database — the Metformin Hydrochloride one above is one of them. If you take anything else, check it against the full list below.

Moderate 85 No known interaction 2,745 (incl. Metformin Hydrochloride)
Taking anything else?

Check Another of Your Medications Against Agaricus Mushroom

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

Everything else you take

See Every Supplement That Interacts With Metformin Hydrochloride

This page covers Agaricus Mushroom only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Metformin Hydrochloride page lists 257 supplements it has a documented interaction with, worst first, each one explained.

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

By severity: 2 major · 217 moderate · 38 minor.

From our pharmacist’s overview on the Metformin Hydrochloride page

“Anyone taking metformin hydrochloride (Riomet ER) should treat this list with genuine care, because two of its 257 entries are rated major. Siberian cocklebur has caused severe hypoglycemia in people and should not be combined with metformin at all, and activated charcoal can adsorb the drug in the gut so less reaches your blood.”

Reviewed by 2 · Jul 18, 2026

Open the Metformin Hydrochloride interaction page

One more smart check

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

We hold 671 real supplement products containing Agaricus Mushroom, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Agaricus Mushroom. Your product may carry other ingredients that interact with Metformin Hydrochloride too, on top of Agaricus Mushroom — 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 Agaricus Mushroom and Metformin Hydrochloride 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 Agaricus Mushroom
Top 25%

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

29 days ago today
Medication Metformin Hydrochloride
Top 5%

#142 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 Agaricus Mushroom

What is Agaricus Mushroom?

  • Immune support
  • General wellness and antioxidant
  • Adjunct interest during cancer care
  • Blood sugar support
  • Cholesterol and heart health

Agaricus mushroom (often Agaricus blazei/subrufescens) is a culinary and medicinal mushroom studied mostly for possible immune and antioxidant effects. The human evidence is limited and not strong enough to recommend it for treating any disease. If you want to try it, talk with your pharmacist or doctor first, especially if you have a health condition or take other medicines.

Read the full Agaricus Mushroom monograph & all interactions
Keep checking

Other Drugs & Agaricus Mushroom

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

0Major
85Moderate
0Minor
2,744No known interaction
85 Moderate 2,744 No interaction
Moderate

85 interactions

Showing 60 of 85 moderate interactions — see all 85 on the Agaricus Mushroom page.

No interaction 2,744 drugs checked — show the list

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

Showing the 60 most looked-up of 2,744 medications checked with no known interaction — see the full Agaricus Mushroom list.

See the full Agaricus Mushroom interactions page
See every supplement checked against Metformin Hydrochloride, 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
Agaricus Mushroom monograph › Uses, safety, and every drug interaction in one place Metformin Hydrochloride supplement interactions › Every supplement checked against Metformin Hydrochloride, 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 Agaricus Mushroom and Metformin Hydrochloride Together: Common Questions

Can you take Agaricus Mushroom with Metformin Hydrochloride?
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 Agaricus Mushroom and Metformin Hydrochloride 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 Hydrochloride and Agaricus Mushroom?

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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.