Drug & supplement interaction

Pata De Vaca + Metformin Hydrochloride

Metformin Hydrochloride brand name: Riomet ER.

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

Pata De Vaca has a moderate interaction with Metformin Hydrochloride. Animal research suggests that pata de vaca may have hypoglycemic effects.

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

Pata De Vaca and Metformin Hydrochloride

Here is the interaction we found between these two, with the evidence behind it.

Moderate

ANTIDIABETES DRUGS

Why this applies to Metformin Hydrochloride

Metformin Hydrochloride falls under ANTIDIABETES DRUGS — the group Pata De Vaca interacts with.

Animal research suggests that pata de vaca may have hypoglycemic effects. However, preliminary clinical research shows that pata de vaca does not reduce blood glucose levels. Until more is known, use with caution. Theoretically, concomitant use of pata de vaca with antidiabetes drugs might affect glucose control and increase the risk of hypoglycemia. Dose adjustments to diabetes medications might be necessary. Some antidiabetes drugs include glimepiride (Amaryl), glyburide (DiaBeta, Glynase PresTab, Micronase), insulin, metformin (Glucophage), pioglitazone (Actos), rosiglitazone (Avandia), and others.
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 simple version: pata de vaca is a tea that folks use to help nudge blood sugar down, which is why it's nicknamed 'vegetable insulin.' Since your metformin is already working to lower glucose, adding something with its own potential sugar-lowering effect could, in theory, stack the two together and push your blood sugar too low. That can show up as shakiness, sweating, dizziness, hunger, or feeling foggy.

I want to be honest about the evidence, though. This concern comes from animal studies, and the small bit of human research we have did not show pata de vaca lowering blood sugar. So this is more of a 'be aware' than a 'be alarmed.' If you'd like to try it, please check with your pharmacist or doctor first and keep an eye on your readings.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Russo EM, Reichelt AA, De Sa JR, et al. Clinical trial of Myrcia uniflora and Bauhinia forficata leaf extracts in normal and diabetic patients. Braz J Med Biol Res 1990;23(1):11-20.
  2. da Cunha AM, Menon S, Menon R, et al. Hypoglycemic activity of dried extracts of Bauhinia forficata Link. Phytomedicine 2010;17(1):37-41. PubMed
  3. Lino Cde S, Diogenes JP, Pereira BA, et al. Antidiabetic activity of Bauhinia forficata extracts in alloxan-diabetic rats. Biol Pharm Bull 2004;27(1):125-7. PubMed
  4. Silva FR, Szpoganicz B, Pizzolatti MG, et al. Acute effect of Bauhinia forficata on serum glucose levels in normal and alloxan-induced diabetic rats. J Ethnopharmacol 2002;83(1-2):33-7. PubMed
  5. Pepato MT, Keller EH, Baviera AM, et al. Anti-diabetic activity of Bauhinia forficata decoction in streptozotocin-diabetic rats. J Ethnopharmacol 2002;81(2):191-7. PubMed
  6. Jorge AP, Horst H, de Sousa E, et al. Insulinomimetic effects of kaempferitrin on glycaemia and on 14C-glucose uptake in rat soleus muscle. Chem Biol Interact 2004;149(2-3):89-96. PubMed
  7. de Sousa E, Zanatta L, Seifriz I, et al. Hypoglycemic effect and antioxidant potential of kaempferol-3,7-O-(alpha)-dirhamnoside from Bauhinia forficata leaves. J Nat Prod 2004;67(5):829-32.
  8. Vasconcelos F, Sampaio SV, Garofalo MA, et al. Insulin-like effects of Bauhinia forficata aqueous extract upon Tityus serrulatus scorpion envenoming. J Ethnopharmacol 2004;95(2-3):385-92. 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

Pata De Vaca Also Interacts With Other Medications

Pata De Vaca has 85 moderate known drug interactions in our database — the Metformin Hydrochloride one above is one of them. If you take anything else, check it against the full list below.

Moderate 85 No known interaction 2,745 (incl. Metformin Hydrochloride)
Taking anything else?

Check Another of Your Medications Against Pata De Vaca

Covers the 2,830 medications we’ve checked against Pata De Vaca. Pick one to open its full report.

Everything else you take

See Every Supplement That Interacts With Metformin Hydrochloride

This page covers Pata De Vaca only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Metformin Hydrochloride 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 Metformin Hydrochloride page

“Anyone taking metformin hydrochloride (Riomet ER) should treat this list with genuine care, because two of its 257 entries are rated major. Siberian cocklebur has caused severe hypoglycemia in people and should not be combined with metformin at all, and activated charcoal can adsorb the drug in the gut so less reaches your blood.”

Reviewed by 2 · Jul 18, 2026

Open the Metformin Hydrochloride interaction page

One more smart check

Taking Pata De Vaca as Part of a Dietary Supplement Product? Check It for Interactions

We hold 7 real supplement products containing Pata De Vaca, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Pata De Vaca. Your product may carry other ingredients that interact with Metformin Hydrochloride too, on top of Pata De Vaca — 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 Pata De Vaca and Metformin Hydrochloride 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 Pata De Vaca
Steady interest

#1,346 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Metformin Hydrochloride
Top 5%

#142 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 Pata De Vaca

What is Pata De Vaca?

  • Blood sugar support
  • Diabetes (traditional use)
  • Diuretic
  • Kidney and urinary health
  • General tonic

Pata de Vaca is a South American plant whose leaves are traditionally brewed as a tea to help support blood sugar, earning it the nickname 'vegetable insulin.' Human evidence is very limited, so it should not replace prescribed diabetes treatment. Talk to your pharmacist or doctor before using it, especially if you take blood-sugar medications.

Read the full Pata De Vaca monograph & all interactions
Keep checking

Other Drugs & Pata De Vaca

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

0Major
85Moderate
0Minor
2,744No known interaction
85 Moderate 2,744 No interaction
Moderate

85 interactions

Showing 60 of 85 moderate interactions — see all 85 on the Pata De Vaca page.

No interaction 2,744 drugs checked — show the list

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

Showing the 60 most looked-up of 2,744 medications checked with no known interaction — see the full Pata De Vaca list.

See the full Pata De Vaca interactions page
See every supplement checked against Metformin Hydrochloride, 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
Pata De Vaca monograph › Uses, safety, and every drug interaction in one place Metformin Hydrochloride supplement interactions › Every supplement checked against Metformin Hydrochloride, 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 Pata De Vaca and Metformin Hydrochloride Together: Common Questions

Can you take Pata De Vaca with Metformin Hydrochloride?
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.
How serious is the Pata De Vaca and Metformin Hydrochloride 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 Metformin Hydrochloride and Pata De Vaca?

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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.