Drug & supplement interaction

Green Coffee + pioglitazone, metformin

pioglitazone, metformin brand name: ActoPlus Met.

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

pioglitazone, metformin falls into 2 drug categories that Green Coffee can interact with; the most serious is rated moderate. Theoretically, caffeine might increase the levels and clinical effects of pioglitazone.

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

Green Coffee and pioglitazone, metformin

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

Why Are There 2 Interactions?

Green Coffee interacts with whole categories of medication. pioglitazone, metformin falls into 2 of those categories, so it can interact with Green Coffee in 2 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 2
Theoretically, caffeine might increase the levels and clinical effects of pioglitazone.
Green coffee 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

Your combo pill, ActoPlus Met, pairs pioglitazone with metformin. The thing worth flagging here is the caffeine in green coffee and how it may nudge the pioglitazone side of that pill. In animal studies, caffeine appeared to let pioglitazone linger longer in the body and reach higher levels, which boosted its blood-sugar-lowering effect a bit. In real terms, that could mean lower blood sugar than expected, so watch for shakiness, sweating, dizziness, or feeling unusually tired.

I want to be honest: this is theoretical, based only on lab and animal work, not human studies. So please do not panic or change anything. If you take ActoPlus Met daily and want to add a green coffee supplement, just check with 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 2

Why this applies to pioglitazone, metformin

pioglitazone, metformin falls under ANTIDIABETES DRUGS — the group Green Coffee interacts with.

Theoretically, taking green coffee and antidiabetes drugs might interfere with blood glucose control.
In clinical research, green coffee extract results in modest reductions in blood glucose levels in various populations. However, other reports claim that caffeine might increase or decrease blood sugar levels.
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 short version: this is a minor, unlikely interaction, so I don't want you to lose sleep over it. ActoPlus Met combines pioglitazone and metformin, both of which work to lower your blood sugar. Green coffee, thanks to its chlorogenic acid, may also nudge blood sugar down a little. So in theory, stacking them could push your numbers slightly lower than expected.

The catch is that green coffee also contains caffeine, and caffeine has been reported to either raise or lower blood sugar, so the net effect is genuinely unpredictable. The evidence here is on the weaker side. If you'd like to try a green coffee supplement, just check your readings a bit more closely at first and watch for signs of low sugar like shakiness, sweating, or feeling lightheaded. A quick chat with your pharmacist or doctor before starting is the safest move.

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
  3. Thom E. The effect of chlorogenic acid enriched coffee on glucose absorption in healthy volunteers and its effect on body mass when used long-term in overweight and obese people. J Int Med Res 2007;35:900-8. PubMed
  4. Blum J, Lemaire B, and Lafay S. Effect of a green decaffeinated coffee extract on glycaemia: a pilot prospective study. Nutrafoods 2007;6(3):13-17.
  5. Thong FS and Graham TE. Caffeine-induced impairment of glucose tolerance is abolished by beta-adrenergic receptor blockade in humans. J Appl Physiol (1985). 2002 Jun;92:2347-52.
  6. Greer F, Hudson R, Ross R, et al. Caffeine ingestion decreases glucose disposal during a hyperinsulinemic-euglycemic clamp in sedentary humans. Diabetes. 2001 Oct;50:2349-54. PubMed
  7. Keijzers GB, De Galan BE, Tack CJ, et al. Caffeine can decrease insulin sensitivity in humans. Diabetes Care. 2002 Feb;25:364-9. PubMed
  8. Johnston KL, Clifford MN, Morgan LM. Coffee acutely modifies gastrointestinal hormone secretion and glucose tolerance in humans: glycemic effects of chlorogenic acid and caffeine. Am J Clin Nutr. 2003 Oct;78:728-33. PubMed
  9. Chen Y, Zhao Y, Wang Y, et al. The influence of green coffee bean extract supplementation on blood glucose levels: A systematic review and dose-response meta-analysis of randomized controlled trials. Phytother Res. 2020;34(9):2159-2169. 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

Green Coffee Also Interacts With Other Medications

Green Coffee has 8 major, 441 moderate, 222 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.

Major 8 Moderate 441 Minor 222 No known interaction 2,159 (incl. pioglitazone, metformin)
Taking anything else?

Check Another of Your Medications Against Green Coffee

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

Everything else you take

See Every Supplement That Interacts With pioglitazone, metformin

This page covers Green Coffee 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 Green Coffee as Part of a Dietary Supplement Product? Check It for Interactions

We hold 1,716 real supplement products containing Green Coffee, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Green Coffee. Your product may carry other ingredients that interact with pioglitazone, metformin too, on top of Green Coffee — 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 Green Coffee 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 Green Coffee
Steady interest

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

29 days ago today
Medication pioglitazone, metformin
Steady interest

#1,692 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 Green Coffee

What is Green Coffee?

Green Coffee
  • Weight loss
  • High blood pressure
  • Blood sugar control
  • Antioxidant support
  • General energy

Green coffee is the unroasted bean of the coffee plant, prized for its high chlorogenic acid content. Some early studies suggest modest benefits for weight, blood pressure, and blood sugar, but the evidence is limited and far from conclusive. It contains caffeine, so people sensitive to stimulants should use caution and check with a pharmacist or doctor first.

Read the full Green Coffee monograph & all interactions
Keep checking

Other Drugs & Green Coffee

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

8Major
441Moderate
222Minor
2,158No known interaction
8 Major 441 Moderate 222 Minor 2,158 No interaction
Major

8 interactions

Moderate

441 interactions

Showing 60 of 441 moderate interactions — see all 441 on the Green Coffee page.

Minor

222 interactions

Showing 60 of 222 minor interactions — see all 222 on the Green Coffee page.

No interaction 2,158 drugs checked — show the list

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

Showing the 60 most looked-up of 2,158 medications checked with no known interaction — see the full Green Coffee list.

See the full Green Coffee 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
Green Coffee 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 Green Coffee and pioglitazone, metformin Together: Common Questions

Can you take Green Coffee 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 2 interactions listed for Green Coffee and pioglitazone, metformin?
pioglitazone, metformin belongs to more than one drug category, and Green Coffee 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 Green Coffee 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

Still Have a Question About pioglitazone, metformin and Green Coffee?

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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.