Drug & supplement interaction

Pu-erh Tea + Glipizide, Metformin

Glipizide, Metformin brand name: Metaglip.

Minor Interaction
The bottom line Minor

Glipizide, Metformin falls into 2 drug categories that Pu-erh Tea can interact with; the most serious is rated minor. Theoretically, taking pu-erh tea with antidiabetes drugs might interfere with blood glucose control.

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

Pu-erh Tea and Glipizide, Metformin

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

Why Are There 2 Interactions?

Pu-erh Tea interacts with whole categories of medication. Glipizide, Metformin falls into 2 of those categories, so it can interact with Pu-erh Tea 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 Glipizide, Metformin

Glipizide, Metformin falls under ANTIDIABETES DRUGS — the group Pu-erh Tea interacts with.

Theoretically, taking pu-erh tea with antidiabetes drugs might interfere with blood glucose control.
Pu-erh tea contains caffeine. 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

Metaglip combines two diabetes medicines: glipizide, which nudges your body to release more insulin, and metformin, which lowers the sugar your liver makes. The concern with pu-erh tea here is really about its caffeine, not the tea leaves themselves. Caffeine can occasionally tug blood sugar in either direction, so in theory it could make your numbers a little harder to predict.

Honestly, this is a minor and unlikely interaction, and the evidence behind it is weak. A cup or two of pu-erh with meals usually won't cause trouble. Just be aware that the glipizide part can already cause low blood sugar (shakiness, sweating, dizziness), so if you drink a lot of caffeinated tea, keep an eye on your readings and mention your habits to your pharmacist or doctor.

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)

2 of 2
Theoretically, metformin might increase the levels and adverse effects of caffeine.
Pu-erh tea 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 something a little different about this pairing. The concern isn't that pu-erh tea changes how your Metaglip (glipizide and metformin) works. It's actually the other way around. Lab and animal studies hint that the metformin part may slow down how your body clears caffeine, and pu-erh tea naturally contains caffeine. So in theory the caffeine could hang around a bit longer and feel a little stronger.

What that might look like is the usual caffeine stuff: feeling jittery, a faster heartbeat, or trouble sleeping. To be honest, this is a theoretical idea based on animal data, not something we see causing real problems in people. A cup or two of tea is unlikely to be an issue. If you drink a lot or notice the jitters, just mention it to your pharmacist or doctor.

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

Pu-erh Tea Also Interacts With Other Medications

Pu-erh Tea has 9 major, 448 moderate, 209 minor known drug interactions in our database — the Glipizide, Metformin one above is among them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Pu-erh Tea

Covers the 2,830 medications we’ve checked against Pu-erh Tea. Pick one to open its full report.

Everything else you take

See Every Supplement That Interacts With Glipizide, Metformin

This page covers Pu-erh Tea only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Glipizide, Metformin page lists 307 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), Adrafinil (moderate) and African Wild Potato (moderate).

By severity: 2 major · 257 moderate · 48 minor.

From our pharmacist’s overview on the Glipizide, Metformin page

“Glipizide and metformin (Metaglip) already work hard to pull blood sugar down, which is exactly why this list of 307 ingredients deserves genuine vigilance rather than a shrug. Most of them, 239, can lower glucose on their own, and stacked on this pill the combined effect can tip into true hypoglycemia.”

Reviewed by 2 · Jul 18, 2026

Open the Glipizide, Metformin interaction page

How much people look this up

Where Pu-erh Tea and Glipizide, 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 Pu-erh Tea
Steady interest

#1,338 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Glipizide, Metformin
Top half

#1,081 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 Pu-erh Tea

What is Pu-erh Tea?

  • Weight management
  • Cholesterol and heart health
  • Digestion after meals
  • Mental alertness
  • General antioxidant support

Pu-erh tea is a fermented, aged form of tea made from the same plant as green and black tea. It is enjoyed worldwide as a beverage and is sometimes promoted for weight loss, cholesterol, and digestion, but human evidence for these uses is limited. As a normal drink it is generally well tolerated, though it does contain caffeine.

Read the full Pu-erh Tea monograph & all interactions
Keep checking

Other Drugs & Pu-erh Tea

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

9Major
448Moderate
209Minor
2,163No known interaction
Major

9 interactions

Moderate

448 interactions

Showing 60 of 448 moderate interactions — see all 448 on the Pu-erh Tea page.

Minor

209 interactions

Showing 60 of 209 minor interactions — see all 209 on the Pu-erh Tea page.

No interaction 2,163 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 Pu-erh Tea and Glipizide, Metformin Together: Common Questions

Can you take Pu-erh Tea with Glipizide, 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 Pu-erh Tea and Glipizide, Metformin?
Glipizide, Metformin belongs to more than one drug category, and Pu-erh Tea 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 Pu-erh Tea and Glipizide, 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.