Drug & supplement interaction

Cola Nut + pioglitazone, metformin

pioglitazone, metformin brand name: ActoPlus Met.

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

pioglitazone, metformin falls into 3 drug categories that Cola Nut can interact with; the most serious is rated moderate. Theoretically, cola nut might increase the levels and clinical effects of pioglitazone.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions3
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Cola Nut and pioglitazone, metformin

These two interact in 3 distinct ways. Each one is explained separately below.

Why Are There 3 Interactions?

Cola Nut interacts with whole categories of medication. pioglitazone, metformin falls into 3 of those categories, so it can interact with Cola Nut in 3 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

PIOGLITAZONE (Actos)

1 of 3
Theoretically, cola nut might increase the levels and clinical effects of pioglitazone.
Cola nut contains caffeine. Animal research suggests that caffeine can modestly increase the maximum concentration, area under the curve, and half-life of pioglitazone, and also reduce its clearance. This increased the antidiabetic effects of pioglitazone. However, the exact mechanism of this interaction is unclear.
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 with your ActoPlus Met (that's pioglitazone plus metformin) and cola nut. The caffeine in cola nut is the part that matters here. In animal studies, caffeine seemed to slow how the body clears pioglitazone, letting a bit more of it hang around and pushing its blood-sugar-lowering effect a little stronger.

So the theoretical concern is that your blood sugar could dip lower than expected, possibly leaving you shaky, sweaty, lightheaded, or hungry. I want to be straight with you though: this is based only on lab and animal data, not human studies, so it's a weak, theoretical signal. Cola in food amounts is unlikely to be a big deal, but if you use concentrated cola nut supplements, mention it to your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Alshabi AM, Alkahtani SA, Shaikh IA, Habeeb MS. Caffeine modulates pharmacokinetic and pharmacodynamic profiles of pioglitazone in diabetic rats: Impact on therapeutics. Saudi Med J 2021;42(2):151-160. PubMed
Minor

ANTIDIABETES DRUGS

2 of 3

Why this applies to pioglitazone, metformin

pioglitazone, metformin 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

Your ActoPlus Met combines two diabetes medicines, pioglitazone and metformin, that work to lower your blood sugar. The concern with cola nut is really about its caffeine. In theory, caffeine can nudge blood sugar in either direction, so it could make your numbers a little less predictable while you are taking these medicines.

Honestly, this is a minor and unlikely interaction, and the evidence is mixed. A cup of caffeinated tea or a normal soda probably won't cause trouble. Concentrated cola nut supplements or large amounts of caffeine are more of a wildcard. If you use them regularly, keep an eye on your home glucose readings for any unusual highs or lows, and check with your pharmacist or doctor before adding a stimulant supplement.

Contact Dr. Brian directly if you have additional questions on this interaction
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
Minor

METFORMIN (Glucophage)

3 of 3
Theoretically, metformin might increase the levels and adverse effects of the caffeine in cola nut.
Cola nut contains caffeine. Animal research suggests that metformin can reduce caffeine metabolism.
Severity Minor 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 with your ActoPlus Met (which combines pioglitazone and metformin) alongside cola nut. The metformin part is the player here. Animal studies hint that metformin may slow down how your body clears caffeine, and since cola nut is basically a caffeine source, that caffeine could hang around a little longer. So this isn't about your diabetes medicine working differently. It's about the caffeine piling up a bit.

In real life that might mean feeling jittery, a racing heart, trouble sleeping, or being slightly more wired than usual. The good news is this is rated minor and only comes from lab and animal work, so it's more of a heads-up than a red flag. If cola nut tends to leave you buzzed, mention it to your pharmacist or doctor.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Mohiuddin, M., Azam, A. T., Amran, M. S., and Hossain, M. A. In vive effects of gliclazide and metformin on the plasma concentration of caffeine in healthy rats. Pak.J Biol Sci 5-1-2009;12(9):734-737.

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 546 moderate, 108 minor known drug interactions in our database — the pioglitazone, metformin one above is among them. If you take anything else, check it against the full list below.

Moderate 546 Minor 108 No known interaction 2,176 (incl. pioglitazone, metformin)
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 pioglitazone, metformin

This page covers Cola Nut only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the pioglitazone, metformin page lists 357 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Beer (major), Grapefruit (major), Siberian Cocklebur (major) and St. John's Wort (major).

By severity: 6 major · 311 moderate · 40 minor.

From our pharmacist’s overview on the pioglitazone, metformin page

“ActoPlus Met pairs pioglitazone with metformin for type 2 diabetes, and the size of this list, 357 supplements in all, reflects how many herbs lower blood sugar on their own. Stacked with the drug, they can push glucose too low; most of the 311 moderate entries work exactly that way.”

Reviewed by 2 · Jul 18, 2026

Open the pioglitazone, metformin 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 pioglitazone, metformin 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 pioglitazone, 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 Cola Nut
Steady interest

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

29 days ago today
Medication pioglitazone, metformin
Steady interest

#2,116 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
546Moderate
108Minor
2,175No known interaction
546 Moderate 108 Minor 2,175 No interaction
Moderate

546 interactions

Showing 60 of 546 moderate interactions — see all 546 on the Cola Nut page.

Minor

108 interactions

Showing 60 of 108 minor interactions — see all 108 on the Cola Nut page.

No interaction 2,175 drugs checked — show the list

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

Showing the 60 most looked-up of 2,175 medications checked with no known interaction — see the full Cola Nut list.

See the full Cola Nut interactions page
See every supplement checked against pioglitazone, metformin, 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
Cola Nut monograph › Uses, safety, and every drug interaction in one place pioglitazone, metformin supplement interactions › Every supplement checked against pioglitazone, metformin, 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 Cola Nut and pioglitazone, metformin Together: Common Questions

Can you take Cola Nut with pioglitazone, 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.
Why are there 3 interactions listed for Cola Nut and pioglitazone, metformin?
pioglitazone, metformin belongs to more than one drug category, and Cola Nut 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 Cola Nut and pioglitazone, 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

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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.