Drug & supplement interaction

Black Mulberry + Metformin, Sitagliptin

Metformin, Sitagliptin brand names: Janumet, Janumet XR.

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

Black Mulberry has a moderate interaction with Metformin, Sitagliptin. Theoretically, black mulberry leaf might increase the risk of hypoglycemia when taken with antidiabetes drugs.

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

Black Mulberry and Metformin, Sitagliptin

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

Moderate

ANTIDIABETES DRUGS

Why this applies to Metformin, Sitagliptin

Metformin, Sitagliptin falls under ANTIDIABETES DRUGS — the group Black Mulberry interacts with.

Theoretically, black mulberry leaf might increase the risk of hypoglycemia when taken with antidiabetes drugs.
One small clinical study shows that black mulberry leaf extract has hypoglycemic effects. This is supported by in vitro research which also suggests that constituents in black mulberry twigs and leaves might have hypoglycemic effects.
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 simple version: Janumet already pairs two blood sugar lowering medicines (metformin and sitagliptin). Black mulberry, especially the leaf extract, contains a compound called DNJ that may also nudge your blood sugar down. Stack the two together and, in theory, your sugar could drop a little lower than expected.

I want to be honest about the strength of this. It's mostly based on lab work and one small study, so it's a theoretical concern, not something we see often. Eating mulberries as a fruit is very unlikely to cause trouble. Concentrated leaf supplements are where I'd be more cautious. Watch for shakiness, sweating, dizziness, or feeling foggy, and check in with your pharmacist or doctor before starting an extract.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  2. Xu LJ, Yu MH, Huang CY, et al. Isoprenylated flavonoids from Morus nigra and their PPAR ? agonistic activities. Fitoterapia 2018;127:109-14. PubMed
  3. Momeni H, Salehi A, Absalan A, Akbari M. Hydro-alcoholic extract of Morus nigra reduces fasting blood glucose and HbA1c% in diabetic patients, probably via competitive and allosteric interaction with alpha-glucosidase enzyme; a clinical trial and in silic

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

Black Mulberry Also Interacts With Other Medications

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

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

Check Another of Your Medications Against Black Mulberry

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

Everything else you take

See Every Supplement That Interacts With Metformin, Sitagliptin

This page covers Black Mulberry only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Metformin, Sitagliptin 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, Sitagliptin page

“Many people prescribed metformin with sitagliptin (Janumet, Janumet XR) for type 2 diabetes also try herbs sold as blood sugar support, fenugreek among the most popular, and that habit is exactly where the risk on this page concentrates. Of 257 documented supplement interactions, 239 can push glucose in the same direction the medicatio…”

Reviewed by 2 · Jul 18, 2026

Open the Metformin, Sitagliptin interaction page

How much people look this up

Where Black Mulberry and Metformin, Sitagliptin 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 Black Mulberry
Top half

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

29 days ago today
Medication Metformin, Sitagliptin
Top 25%

#608 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 Black Mulberry

What is Black Mulberry?

Black Mulberry
  • General antioxidant support
  • Blood sugar support
  • Cholesterol and heart health
  • Digestive health
  • Cold and sore throat remedies (traditional)

Black mulberry is a nutritious fruit rich in antioxidants and vitamins, and it is generally safe to enjoy as a food. Some early research on its leaf and fruit extracts hints at benefits for blood sugar and cholesterol, but the evidence is still limited. Talk with your pharmacist or doctor before using concentrated extracts, especially if you have a health condition.

Read the full Black Mulberry monograph & all interactions
Keep checking

Other Drugs & Black Mulberry

Browse every other medication we’ve checked against Black 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 Black Mulberry page.

No interaction 2,743 drugs checked — show the list

We also checked Black 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 Black Mulberry list.

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

Can you take Black Mulberry with Metformin, Sitagliptin?
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 Black Mulberry and Metformin, Sitagliptin 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, Sitagliptin and Black 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.