Drug & supplement interaction

Carqueja + Metformin, Sitagliptin

Metformin, Sitagliptin brand names: Janumet, Janumet XR.

Moderate Interaction
The bottom line Moderate

Carqueja has a moderate interaction with Metformin, Sitagliptin. Theoretically, carqueja might lower blood glucose levels and might have additive effects when used with antidiabetes drugs.

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

Carqueja and Metformin, Sitagliptin

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

Moderate

ANTIDIABETES DRUGS

Why this applies to Metformin, Sitagliptin

Metformin, Sitagliptin falls under ANTIDIABETES DRUGS — the group Carqueja interacts with.

Theoretically, carqueja might lower blood glucose levels and might have additive effects when used with antidiabetes drugs. This might increase the risk of hypoglycemia in some patients. Monitor blood glucose levels closely. 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: Janumet combines two diabetes medicines, metformin and sitagliptin, and both work to bring your blood sugar down. Carqueja, an herbal bitter tea, has shown in lab and animal studies that it may lower blood sugar too. So if you take them together, the worry is a doubling-up effect that pushes your sugar lower than intended.

If that happens, you might feel shaky, sweaty, dizzy, irritable, or unusually tired, which are classic signs of low blood sugar. I'll be honest though, this is mostly a theoretical concern based on early research, not strong human studies. Don't change anything on your own. Just check your blood sugar regularly and let your doctor or pharmacist know you're using carqueja.

References
  1. Coelho MG, Reis PA, Gava VB, et al. Anti-arthritic effect and subacute toxicological evaluation of Baccharis genistelloides aqueous extract. Toxicol Lett 2004;154:69-80. PubMed
  2. Oliveira AC, Endringer DC, Amorim LA, et al. Effect of the extracts and fractions of Baccharis trimera and Syzygium cumini on glycaemia of diabetic and non-diabetic mice. J Ethnopharmacol 2005;102:465-9. 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

Carqueja Also Interacts With Other Medications

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

Taking anything else?

Check Another of Your Medications Against Carqueja

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

Everything else you take

See Every Supplement That Interacts With Metformin, Sitagliptin

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

“Many people prescribed metformin with sitagliptin (Janumet, Janumet XR) for type 2 diabetes also try herbs sold as blood sugar support, fenugreek among the most popular, and that habit is exactly where the risk on this page concentrates. Of 257 documented supplement interactions, 239 can push glucose in the same direction the medicatio…”

Reviewed by 2 · Jul 18, 2026

Open the Metformin, Sitagliptin interaction page

One more smart check

Taking Carqueja as Part of a Dietary Supplement Product? Check It for Interactions

We hold 3 real supplement products containing Carqueja, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Carqueja. Your product may carry other ingredients that interact with Metformin, Sitagliptin too, on top of Carqueja — 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 Carqueja and Metformin, Sitagliptin 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 Carqueja
Steady interest

#1,134 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Metformin, Sitagliptin
Top half

#999 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 Carqueja

What is Carqueja?

  • Digestive upset and bloating
  • Liver and gallbladder support
  • Blood sugar control
  • Weight loss
  • Anti-inflammatory

Carqueja is a South American herb traditionally used as a bitter tea for digestion, liver complaints, and blood sugar. Human evidence is very limited, so its benefits are not well proven. Because safety data are thin, it should be avoided in pregnancy and breastfeeding and used cautiously by everyone else.

Read the full Carqueja monograph & all interactions
Keep checking

Other Drugs & Carqueja

Browse every other medication we’ve checked against Carqueja — 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
Moderate

85 interactions

Showing 60 of 85 moderate interactions — see all 85 on the Carqueja page.

No interaction 2,744 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 Carqueja and Metformin, Sitagliptin Together: Common Questions

Can you take Carqueja with Metformin, Sitagliptin?
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 Carqueja and Metformin, Sitagliptin 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

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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.