Drug & supplement interaction

Hibiscus Sabdariffa + Metformin, Rosiglitazone

Metformin, Rosiglitazone brand name: Avandamet.

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

Metformin, Rosiglitazone falls into 3 drug categories that Hibiscus Sabdariffa can interact with; the most serious is rated moderate. Theoretically, taking Hibiscus sabdariffa with antidiabetes drugs might increase the risk of hypoglycemia.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions3
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Hibiscus Sabdariffa and Metformin, Rosiglitazone

These two interact in 3 distinct ways. Each one is explained separately below.

Why Are There 3 Interactions?

Hibiscus Sabdariffa interacts with whole categories of medication. Metformin, Rosiglitazone falls into 3 of those categories, so it can interact with Hibiscus Sabdariffa in 3 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

ANTIDIABETES DRUGS

1 of 3

Why this applies to Metformin, Rosiglitazone

Metformin, Rosiglitazone falls under ANTIDIABETES DRUGS — the group Hibiscus Sabdariffa interacts with.

Theoretically, taking Hibiscus sabdariffa with antidiabetes drugs might increase the risk of hypoglycemia.
Most clinical research shows that Hibiscus sabdariffa can reduce blood glucose levels.
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

Avandamet combines two diabetes medicines, metformin and rosiglitazone, that both work to bring your blood sugar down. Hibiscus, especially as a tea, seems to have its own mild blood-sugar-lowering effect. So the concern here is simple addition: stacking hibiscus on top of your medication could push your glucose a little lower than expected.

Keep in mind this is a theoretical caution based on how hibiscus behaves, not strong proof of a problem. Still, it's worth watching for signs of low blood sugar like shakiness, sweating, dizziness, or feeling unusually hungry, particularly if you drink concentrated hibiscus regularly. An occasional cup of tea is unlikely to matter much. If you want to use it routinely, check with your pharmacist or doctor first and keep monitoring your numbers.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Gurrola-Diaz, C. M., Garcia-Lopez, P. M., Sanchez-Enriquez, S., Troyo-Sanroman, R., Andrade-Gonzalez, I., and Gomez-Leyva, J. F. Effects of Hibiscus sabdariffa extract powder and preventive treatment (diet) on the lipid profiles of patients with metaboli
  2. Najafpour Boushehri S, Karimbeiki R, Ghasempour S, et al. The efficacy of sour tea (Hibiscus sabdariffa L.) on selected cardiovascular disease risk factors: A systematic review and meta-analysis of randomized clinical trials. Phytother Res. 2020;34(2):329
  3. Bule M, Albelbeisi AH, Nikfar S, Amini M, Abdollahi M. The antidiabetic and antilipidemic effects of Hibiscus sabdariffa: A systematic review and meta-analysis of randomized clinical trials. Food Res Int. 2020;130:108980. PubMed
Minor

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES

2 of 3

Metformin, Rosiglitazone also falls under CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES.

Theoretically, Hibiscus sabdariffa extract might reduce the metabolism of CYP2C9 substrates.
In vitro research shows that Hibiscus sabdariffa calyx extract inhibits CYP2C9. This interaction has not been reported in humans.
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

Avandamet combines two diabetes medicines. The rosiglitazone part is partly handled by a liver enzyme called CYP2C9, and that's where hibiscus comes in. In a lab dish, hibiscus extract slowed this enzyme down. If that happened in your body, rosiglitazone could clear a bit more slowly and build up slightly, which in theory might mean more of its usual effects like fluid retention, swelling, weight gain, or a bigger drop in blood sugar.

Here's the reassuring part: this is only a theoretical concern from test-tube work, never actually seen in people, and it's rated minor. A cup or two of tart hibiscus tea is unlikely to cause trouble. Still, since hibiscus itself can lower blood pressure, chat with your pharmacist before using concentrated supplements.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Johnson SS, Oyelola FT, Ari T, Juho H. In vitro inhibitory activities of the extract of Hibiscus sabdariffa L. (family Malvaceae) on selected cytochrome P450 isoforms. Afr J Tradit Complement Altern Med. 2013 Apr 12;10(3):533-40.
Minor

CYTOCHROME P450 2C8 (CYP2C8) SUBSTRATES

3 of 3

Metformin, Rosiglitazone also falls under CYTOCHROME P450 2C8 (CYP2C8) SUBSTRATES.

Theoretically, Hibiscus sabdariffa might reduce the metabolism of CYP2C8 substrates.
In vitro research shows that Hibiscus sabdariffa calyx extract inhibits CYP2C8. This interaction has not been reported in humans.
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 for your Avandamet, which combines metformin with rosiglitazone. The rosiglitazone part is cleared by a liver enzyme called CYP2C8. In a test-tube study, hibiscus extract slowed that enzyme down a bit. If that held true in people, rosiglitazone could linger a little longer and build up, which in theory might mean more of its usual effects, like extra fluid retention, swelling in the ankles, weight gain, or a stronger blood-sugar-lowering effect that could tip you toward a low. Hibiscus on its own can also nudge blood pressure down.

That said, this is only lab data and has never actually been seen in humans, so I wouldn't lose sleep over a cup of hibiscus tea. If you want to use concentrated hibiscus supplements regularly, just run it by your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Johnson SS, Oyelola FT, Ari T, Juho H. In vitro inhibitory activities of the extract of Hibiscus sabdariffa L. (family Malvaceae) on selected cytochrome P450 isoforms. Afr J Tradit Complement Altern Med. 2013 Apr 12;10(3):533-40.

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

Hibiscus Sabdariffa Also Interacts With Other Medications

Hibiscus Sabdariffa has 2 major, 265 moderate, 819 minor known drug interactions in our database — the Metformin, Rosiglitazone one above is among them. If you take anything else, check it against the full list below.

Major 2 Moderate 265 Minor 819 No known interaction 1,744 (incl. Metformin, Rosiglitazone)
Taking anything else?

Check Another of Your Medications Against Hibiscus Sabdariffa

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

Everything else you take

See Every Supplement That Interacts With Metformin, Rosiglitazone

This page covers Hibiscus Sabdariffa only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Metformin, Rosiglitazone page lists 315 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Beer (major), Siberian Cocklebur (major), Wine (major) and Acai (moderate).

By severity: 4 major · 268 moderate · 43 minor.

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

“Avandamet pairs metformin with rosiglitazone to manage type 2 diabetes, and its supplement list calls for genuine care rather than a quick skim. Start with the four major-rated entries: alcohol and the herb Siberian cocklebur can each stress the liver, a serious concern with rosiglitazone on board, while activated charcoal can soak up…”

Reviewed by 2 · Jul 18, 2026

Open the Metformin, Rosiglitazone interaction page

How much people look this up

Where Hibiscus Sabdariffa and Metformin, Rosiglitazone 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 Hibiscus Sabdariffa
Top half

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

29 days ago today
Medication Metformin, Rosiglitazone
Top half

#731 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 Hibiscus Sabdariffa

What is Hibiscus Sabdariffa?

Hibiscus Sabdariffa
  • High blood pressure
  • Heart and cholesterol health
  • Digestive upset
  • Antioxidant support
  • Fever and general wellness

Hibiscus sabdariffa is a tart, cranberry-flavored plant most often consumed as a tea, and its best-studied use is for mildly lowering blood pressure. Evidence for other uses is limited, and while hibiscus tea is generally well tolerated in food amounts, concentrated supplements should be used cautiously and avoided in pregnancy. Talk to your pharmacist or doctor before using it for a medical condition.

Read the full Hibiscus Sabdariffa monograph & all interactions
Keep checking

Other Drugs & Hibiscus Sabdariffa

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

2Major
265Moderate
819Minor
1,743No known interaction
2 Major 265 Moderate 819 Minor 1,743 No interaction
Major

2 interactions

Moderate

265 interactions

Showing 60 of 265 moderate interactions — see all 265 on the Hibiscus Sabdariffa page.

Minor

819 interactions

Showing 60 of 819 minor interactions — see all 819 on the Hibiscus Sabdariffa page.

No interaction 1,743 drugs checked — show the list

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

Showing the 60 most looked-up of 1,743 medications checked with no known interaction — see the full Hibiscus Sabdariffa list.

See the full Hibiscus Sabdariffa interactions page
See every supplement checked against Metformin, Rosiglitazone, 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
Hibiscus Sabdariffa monograph › Uses, safety, and every drug interaction in one place Metformin, Rosiglitazone supplement interactions › Every supplement checked against Metformin, Rosiglitazone, 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 Hibiscus Sabdariffa and Metformin, Rosiglitazone Together: Common Questions

Can you take Hibiscus Sabdariffa with Metformin, Rosiglitazone?
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 3 interactions listed for Hibiscus Sabdariffa and Metformin, Rosiglitazone?
Metformin, Rosiglitazone belongs to more than one drug category, and Hibiscus Sabdariffa 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 Hibiscus Sabdariffa and Metformin, Rosiglitazone 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.