Drug & supplement interaction

Cola Nut + Metformin XR

Metformin XR brand name: Glucophage XR.

Minor Interaction
The bottom line Minor

Cola Nut has a minor interaction with Metformin XR. Theoretically, taking cola nut with antidiabetes drugs might interfere with blood glucose control.

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

Cola Nut and Metformin XR

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

Minor

ANTIDIABETES DRUGS

Why this applies to Metformin XR

Metformin XR falls under ANTIDIABETES DRUGS — the group Cola Nut interacts with.

Theoretically, taking cola nut with antidiabetes drugs might interfere with blood glucose control.
Cola nut contains caffeine. Some conflicting reports claim that caffeine might increase or decrease blood sugar.
Severity Minor Likelihood Unlikely Evidence B

Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans..

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

Here's the simple version: cola nut's main active ingredient is caffeine, and the concern is that caffeine could nudge your blood sugar in either direction. That's why it might bump up against what your Metformin XR is trying to do, which is keep your blood sugar steady. This isn't about caffeine changing how metformin is broken down. Metformin isn't really processed by liver enzymes, so it's more about caffeine's own mild effect on blood sugar.

Honestly, the evidence here is weak and the reports even conflict on whether caffeine raises or lowers sugar. So for most people this is a small, unlikely concern. If you use cola nut regularly or notice your numbers acting strange, just mention it to your pharmacist or doctor before changing anything.

References
  1. Watson JM, Jenkins EJ, Hamilton P, et al. Influence of caffeine on the frequency and perception of hypoglycemia in free-living patients with type 1 diabetes. Diabetes Care 2000;23:455-9. PubMed
  2. Bell DG, Jacobs I, Ellerington K. Effect of caffeine and ephedrine ingestion on anaerobic exercise performance. Med Sci Sports Exerc 2001;33:1399-403. 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

Cola Nut Also Interacts With Other Medications

Cola Nut has 547 moderate, 107 minor known drug interactions in our database — the Metformin XR 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 Cola Nut

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

Everything else you take

See Every Supplement That Interacts With Metformin XR

This page covers Cola Nut only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Metformin XR page lists 256 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 · 215 moderate · 39 minor.

From our pharmacist’s overview on the Metformin XR page

“Siberian cocklebur stands alone at the top of this list; its seeds have caused severe low blood sugar in humans, and no one taking metformin XR (Glucophage XR) should use it. Almost everything else here, 239 of the 256 ingredients, affects blood sugar too, so this list earns real caution.”

Reviewed by 2 · Jul 18, 2026

Open the Metformin XR interaction page

One more smart check

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

We hold 2 real supplement products containing Cola Nut, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Cola Nut. Your product may carry other ingredients that interact with Metformin XR too, on top of Cola Nut — 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 Cola Nut and Metformin XR 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 Cola Nut
Steady interest

#1,051 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Metformin XR
Top 25%

#408 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 Cola Nut

What is Cola Nut?

Cola Nut
  • Energy and alertness
  • Mental focus
  • Physical performance
  • Weight loss support
  • Traditional digestive aid

Cola nut is a caffeine-containing seed from West Africa used mainly as a natural stimulant for energy and alertness. Most of its effects come from caffeine, and strong human evidence for specific health benefits is limited. Because of its caffeine content, people sensitive to stimulants and those who are pregnant or have heart conditions should be cautious.

Read the full Cola Nut monograph & all interactions
Keep checking

Other Drugs & Cola Nut

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

0Major
547Moderate
107Minor
2,175No known interaction
Moderate

547 interactions

Showing 60 of 547 moderate interactions — see all 547 on the Cola Nut page.

Minor

107 interactions

Showing 60 of 107 minor interactions — see all 107 on the Cola Nut page.

No interaction 2,175 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 Cola Nut and Metformin XR Together: Common Questions

Can you take Cola Nut with Metformin XR?
There is only a minor interaction, which is usually not serious. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Cola Nut and Metformin XR interaction?
We rate it Minor. This interaction is generally not clinically significant, but it remains worth noting and discussing with your pharmacist.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Metformin XR and Cola Nut?

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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.