Drug & supplement interaction

Ilex Guayusa + Pioglitazone

Pioglitazone brand name: Actos.

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

Pioglitazone falls into 2 drug categories that Ilex Guayusa 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

Ilex Guayusa and Pioglitazone

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

Why Are There 2 Interactions?

Ilex Guayusa interacts with whole categories of medication. Pioglitazone falls into 2 of those categories, so it can interact with Ilex Guayusa 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.
Ilex guayusa 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 guayusa, which is really just a caffeine source, and your pioglitazone (Actos). Some animal studies hint that caffeine may slow how fast your body clears pioglitazone, letting a bit more of it hang around. In theory, that could make the medication's blood-sugar-lowering effect a touch stronger.

What might you notice? Mostly signs of low blood sugar like shakiness, sweating, dizziness, or feeling unusually hungry, especially if you skip meals. I want to be honest, though: this is theoretical and only seen in lab and animal work, not in people, so most folks drinking guayusa won't run into trouble. Still, if you enjoy it regularly, mention it to your pharmacist or doctor and keep an eye on your sugar readings.

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

Pioglitazone falls under ANTIDIABETES DRUGS — the group Ilex Guayusa interacts with.

Theoretically, taking Ilex guayusa with antidiabetes drugs might increase the risk of hypoglycemia.
Animal research in a model of hyperglycemia suggests that Ilex guayusa may have antihyperglycemic effects, although it does not appear to lower glucose levels when compared with baseline. This effect has not been evaluated in humans.
Severity Minor Likelihood Unlikely Evidence D

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 gist if you enjoy guayusa tea while taking pioglitazone (Actos) for your type 2 diabetes. On paper, guayusa might have a mild blood sugar lowering effect, so combining it with a diabetes medication could in theory nudge your sugar a little lower than expected. If that happened, you might notice signs of low blood sugar like shakiness, sweating, dizziness, or feeling unusually hungry.

That said, I want to keep this in perspective. This concern comes only from animal research, and the tea didn't actually drop glucose below normal even in those studies. It has never been tested in people, so the real risk is considered minor and unlikely. Pioglitazone itself rarely causes lows on its own. Enjoy your tea, keep an eye on your numbers, and mention it to your pharmacist or doctor if you have questions.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Swanston-Flatt SK, Day C, Flatt PR, Gould BJ, Bailey CJ. Glycaemic effects of traditional European plant treatments for diabetes. Studies in normal and streptozotocin diabetic mice. Diabetes Res 1989;10(2):69-73.
  2. Mello TC, Dias DDS, Bernardes N, et al. Ilex Guayusa Tea Improves Glycaemia and Autonomic Modulation in Female Streptozotocin-Induced Diabetic Rats. Pharmaceuticals (Basel) 2025;18(3):316. 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

Ilex Guayusa Also Interacts With Other Medications

Ilex Guayusa has 8 major, 469 moderate, 127 minor known drug interactions in our database — the Pioglitazone one above is among them. If you take anything else, check it against the full list below.

Major 8 Moderate 469 Minor 127 No known interaction 2,226 (incl. Pioglitazone)
Taking anything else?

Check Another of Your Medications Against Ilex Guayusa

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

Everything else you take

See Every Supplement That Interacts With Pioglitazone

This page covers Ilex Guayusa only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Pioglitazone page lists 356 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 · 309 moderate · 41 minor.

From our pharmacist’s overview on the Pioglitazone page

“Most of what appears on this pioglitazone (Actos) list shares one trait: the ingredients lower blood sugar on their own, which sounds helpful until you remember pioglitazone already does that job for people with type 2 diabetes. Stacked together, they can push glucose too low, and I would read this list with genuine care.”

Reviewed by 2 · Jul 18, 2026

Open the Pioglitazone interaction page

How much people look this up

Where Ilex Guayusa and Pioglitazone 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 Ilex Guayusa
Steady interest

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

29 days ago today
Medication Pioglitazone
Steady interest

#2,141 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 Ilex Guayusa

What is Ilex Guayusa?

  • Energy and alertness
  • Mental focus
  • Antioxidant support
  • Appetite control
  • Athletic and physical performance

Ilex guayusa is a caffeine-containing holly leaf from the Amazon, traditionally brewed as a tea for energy and alertness, much like yerba mate or green tea. There is limited human research confirming specific health benefits, and its main reliable effect comes from its caffeine content. Because it is a stimulant, use it cautiously and check with your pharmacist or doctor if you have heart concerns or are pregnant.

Read the full Ilex Guayusa monograph & all interactions
Medication

About Pioglitazone

What Is Pioglitazone Used For?

Brand name: Actos

Pioglitazone is used with diet and exercise to improve blood sugar (glycemic) control in adults with type 2 diabetes. It can be used alone or combined with other diabetes medicines.

It does not work without insulin in your body. It should not be used to treat type 1 diabetes or diabetic ketoacidosis (a dangerous buildup of acids in the blood). Actos and pioglitazone hydrochloride tablets carry this same use.

See full Pioglitazone drug information
Keep checking

Other Drugs & Ilex Guayusa

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

8Major
469Moderate
127Minor
2,225No known interaction
8 Major 469 Moderate 127 Minor 2,225 No interaction
Major

8 interactions

Moderate

469 interactions

Showing 60 of 469 moderate interactions — see all 469 on the Ilex Guayusa page.

Minor

127 interactions

Showing 60 of 127 minor interactions — see all 127 on the Ilex Guayusa page.

No interaction 2,225 drugs checked — show the list

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

Showing the 60 most looked-up of 2,225 medications checked with no known interaction — see the full Ilex Guayusa list.

See the full Ilex Guayusa interactions page
See every supplement checked against Pioglitazone, 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
Ilex Guayusa monograph › Uses, safety, and every drug interaction in one place Pioglitazone supplement interactions › Every supplement checked against Pioglitazone, ranked by severity Pioglitazone drug information › The full plain-English guide to this medication 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 Ilex Guayusa and Pioglitazone Together: Common Questions

Can you take Ilex Guayusa with Pioglitazone?
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 Ilex Guayusa and Pioglitazone?
Pioglitazone belongs to more than one drug category, and Ilex Guayusa 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 Ilex Guayusa and Pioglitazone 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 and Ilex Guayusa?

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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.