Drug & supplement interaction

White Mulberry + Metformin Hydrochloride

Metformin Hydrochloride brand name: Riomet ER.

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

Metformin Hydrochloride falls into 2 drug categories that White Mulberry can interact with; the most serious is rated moderate. Theoretically, white mulberry leaf might increase the risk of hypoglycemia when taken with antidiabetes drugs.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

White Mulberry and Metformin Hydrochloride

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

White Mulberry interacts with whole categories of medication. Metformin Hydrochloride falls into 2 of those categories, so it can interact with White Mulberry in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

ANTIDIABETES DRUGS

1 of 2

Why this applies to Metformin Hydrochloride

Metformin Hydrochloride falls under ANTIDIABETES DRUGS — the group White Mulberry interacts with.

Theoretically, white mulberry leaf might increase the risk of hypoglycemia when taken with antidiabetes drugs.
Clinical research shows that white mulberry leaf can lower blood glucose levels. Advise patients to monitor glucose levels closely.
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 short version: white mulberry leaf can gently lower blood sugar on its own, mostly by slowing how quickly your gut absorbs sugar after a meal. Your metformin is already working to keep your numbers down, so stacking the two together could in theory push your blood sugar a little lower than expected. The good news is that metformin by itself rarely causes true lows, so the bigger concern would be if you also take insulin or a sulfonylurea alongside it.

To be honest, this interaction is theoretical, based on how the two work rather than strong studies. Food or tea amounts are unlikely to matter much. With a concentrated mulberry supplement, just watch for shaky, sweaty, or lightheaded feelings, check your glucose a bit more often, and chat with your pharmacist or doctor before adding it.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Andallu B, Suryakantham V, Lakshmi Srikanthi B, Reddy GK. Effect of mulberry (Morus indica L.) therapy on plasma and erythrocyte membrane lipids in patients with type 2 diabetes. Clin Chim Acta 2001;314:47-53. PubMed
  2. Mudra M, Ercan-Fang N, Zhong L, et al. Influence of mulberry leaf extract on the blood glucose and breath hydrogen response to ingestion of 75 g sucrose by type 2 diabetic and control subjects. Diabetes Care 2007;30:1272-4. PubMed
  3. Kimura T, Nakagawa K, Kubota H, et al. Food-grade mulberry powder enriched with 1-deoxynojirimycin suppresses the elevation of postprandial blood glucose in humans. J Agric Food Chem 2007;55:5869-74. PubMed
  4. Thaipitakwong T, Supasyndh O, Rasmi Y, Aramwit P. A randomized controlled study of dose-finding, efficacy, and safety of mulberry leaves on glycemic profiles in obese persons with borderline diabetes. Complement Ther Med. 2020;49:102292. PubMed
  5. Thondre PS, Lightowler H, Ahlstrom L, Gallagher A. Mulberry leaf extract improves glycaemic response and insulaemic response to sucrose in healthy subjects: results of a randomized, double blind, placebo-controlled study. Nutr Metab (Lond) 2021;18(1):41. PubMed
Moderate

ORGANIC CATION TRANSPORTER 2 (OCT2) SUBSTRATES

2 of 2

Metformin Hydrochloride also falls under ORGANIC CATION TRANSPORTER 2 (OCT2) SUBSTRATES.

Theoretically, white mulberry leaf might slow the elimination and increase the adverse effects of drugs which are OCT2 substrates.
Animal research shows that coadministration of white mulberry leaf extract with metformin, an OCT2 substrate, slows the renal elimination of metformin via inhibition of OCT2 activity. OCT2 is expressed in the kidneys and is responsible for transporting cationic drugs into tubular epithelial cells in order to be excreted in the urine.
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 white mulberry and metformin. Your kidneys clear metformin out of your body using a little transporter called OCT2. In animal studies, white mulberry leaf seemed to slow that transporter down. If less metformin gets flushed out, more of it can linger in your system, which could nudge up the usual side effects like nausea, upset stomach, diarrhea, or a metallic taste.

I want to be honest about the strength here: this is based on lab and animal research, not human studies, so it's more of a theoretical heads-up than a proven problem. On top of that, both lower blood sugar, so the combo could push your numbers a bit low. Tea or food amounts likely matter less than concentrated capsules. Just check with your pharmacist or doctor before adding a supplement.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Huh HW, Na YG, Bang KH, et al. Extended intake of mulberry leaf extract delayed metformin elimination via inhibiting the organic cation transporter 2. Pharmaceutics. 2020;12(1):49. 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

White Mulberry Also Interacts With Other Medications

White Mulberry has 86 moderate known drug interactions in our database — the Metformin Hydrochloride one above is among them. If you take anything else, check it against the full list below.

Moderate 86 No known interaction 2,744 (incl. Metformin Hydrochloride)
Taking anything else?

Check Another of Your Medications Against White Mulberry

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

From our Q&A

Questions About White Mulberry or Metformin Hydrochloride

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

This page covers White Mulberry 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 Agaricus Mushroom (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 White Mulberry as Part of a Dietary Supplement Product? Check It for Interactions

We hold 282 real supplement products containing White Mulberry, each one broken down to its full ingredient list — and combination products often carry several ingredients besides White Mulberry. Your product may carry other ingredients that interact with Metformin Hydrochloride too, on top of White Mulberry — 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 White Mulberry 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 White Mulberry
Top half

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

29 days ago today
Medication Metformin Hydrochloride
Top 10%

#147 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 White Mulberry

What is White Mulberry?

White Mulberry
  • Blood sugar support
  • High cholesterol
  • Weight management
  • Antioxidant support
  • High blood pressure (traditional use)

White mulberry leaf is most studied for helping blunt the rise in blood sugar after meals, but the human evidence is limited and not strong. It is generally well tolerated as a food and tea, but talk to your pharmacist or doctor before using concentrated supplements, especially if you take diabetes medicine.

Read the full White Mulberry monograph & all interactions
Keep checking

Other Drugs & White Mulberry

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

0Major
86Moderate
0Minor
2,743No known interaction
86 Moderate 2,743 No interaction
Moderate

86 interactions

Showing 60 of 86 moderate interactions — see all 86 on the White Mulberry page.

No interaction 2,743 drugs checked — show the list

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

Showing the 60 most looked-up of 2,743 medications checked with no known interaction — see the full White Mulberry list.

See the full White Mulberry 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
White Mulberry 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 White Mulberry and Metformin Hydrochloride Together: Common Questions

Can you take White Mulberry 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.
Why are there 2 interactions listed for White Mulberry and Metformin Hydrochloride?
Metformin Hydrochloride belongs to more than one drug category, and White Mulberry interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the White Mulberry 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 White Mulberry?

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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.