Drug & supplement interaction

Ilex Guayusa + Alogliptin, Metformin

Alogliptin, Metformin brand name: Kazano.

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

Alogliptin, Metformin falls into 2 drug categories that Ilex Guayusa can interact with; the most serious is rated minor. Theoretically, taking Ilex guayusa with antidiabetes drugs might increase the risk of hypoglycemia.

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

Ilex Guayusa and Alogliptin, Metformin

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. Alogliptin, Metformin 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 (Minor).

Minor

ANTIDIABETES DRUGS

1 of 2

Why this applies to Alogliptin, Metformin

Alogliptin, Metformin 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 bottom line with guayusa tea and Kazano (which combines alogliptin and metformin to lower your blood sugar). On paper, there's a thought that guayusa might add a little extra blood-sugar-lowering effect on top of your medication, which could in theory nudge you toward hypoglycemia (low blood sugar). That can show up as shakiness, sweating, dizziness, or feeling suddenly hungry or confused.

But I want to keep this in perspective. This idea comes only from animal research, and it hasn't been tested in people. Honestly, any effect is most likely from the caffeine acting as a stimulant rather than a true sugar-lowering action. Enjoying guayusa as a tea is unlikely to be a problem. If you drink a lot or take concentrated supplements, just mention it to your pharmacist or doctor.

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
Minor

METFORMIN (Glucophage)

2 of 2
Theoretically, metformin might increase the levels and adverse effects of caffeine.
Ilex guayusa contains caffeine. Animal research suggests that metformin can reduce caffeine metabolism. Theoretically, concomitant use can increase caffeine serum concentrations and the risk of caffeine adverse effects.
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 Kazano (which combines alogliptin and metformin) and guayusa tea. The interaction isn't really about your diabetes medicine getting stronger or weaker. Instead, it works the other way around: the metformin part may slow down how fast your body clears caffeine, and guayusa is basically a caffeine-rich tea. So the caffeine could hang around longer and hit a little harder.

In plain terms, you might notice more jitteriness, a racing heart, trouble sleeping, or feeling wired. The good news is this is only a theoretical concern based on animal research, so it's rated minor. A normal cup or two probably won't cause trouble, but if you feel buzzy or your heart is pounding, ease up and check with 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

Ilex Guayusa Also Interacts With Other Medications

Ilex Guayusa has 8 major, 470 moderate, 126 minor known drug interactions in our database — the Alogliptin, Metformin one above is among them. If you take anything else, check it against the full list below.

Major 8 Moderate 470 Minor 126 No known interaction 2,226 (incl. Alogliptin, Metformin)
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 Alogliptin, Metformin

This page covers Ilex Guayusa only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Alogliptin, Metformin 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 Alogliptin, Metformin page

“Kazano combines alogliptin and metformin to lower blood sugar, and nearly everything on this list pushes on that same lever, so I treat these pairings with real caution. Most entries are herbs and supplements that lower glucose on their own, and stacked on the drug they raise the risk of hypoglycemia, a sugar drop steep enough to cause…”

Reviewed by 2 · Jul 18, 2026

Open the Alogliptin, Metformin interaction page

How much people look this up

Where Ilex Guayusa and Alogliptin, 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 Ilex Guayusa
Steady interest

#1,114 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Alogliptin, Metformin
Top 25%

#481 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
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
470Moderate
126Minor
2,225No known interaction
8 Major 470 Moderate 126 Minor 2,225 No interaction
Major

8 interactions

Moderate

470 interactions

Showing 60 of 470 moderate interactions — see all 470 on the Ilex Guayusa page.

Minor

126 interactions

Showing 60 of 126 minor interactions — see all 126 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 Alogliptin, 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
Ilex Guayusa monograph › Uses, safety, and every drug interaction in one place Alogliptin, Metformin supplement interactions › Every supplement checked against Alogliptin, 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 Ilex Guayusa and Alogliptin, Metformin Together: Common Questions

Can you take Ilex Guayusa with Alogliptin, Metformin?
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.
Why are there 2 interactions listed for Ilex Guayusa and Alogliptin, Metformin?
Alogliptin, Metformin 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 Alogliptin, Metformin 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

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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.