Drug & supplement interaction

Germander + Metformin

Metformin brand names: Glucophage, Metformin.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Germander and Metformin in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Germander and Metformin

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Metformin and Germander in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

Worth understanding: our licensed dataset holds no drug-interaction record for Germander at all — not against Metformin, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Germander safety at a glance

Germander overall Avoid Germander has been linked to serious, sometimes fatal liver injury and should be avoided.
Pregnancy Likely Unsafe When used orally. Read the full pregnancy detail
Breastfeeding Likely Unsafe When used orally. Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Metformin and Germander? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

No Interaction Found — But Data Suggests Germander and Metformin May Share a Side Effect

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do. One of them is worth acting on rather than waiting out — marked below.

  • Liver problems Worth acting on Additional detail

    Germander

    “Orally, germander has been associated with hepatitis, liver cell necrosis, and death.”

    Germander · Natural Medicines adverse-effect record, reported in hepatitis.

    5 sources cited
    1. 271. Bruneton J. Pharmacognosy, Phytochemistry, Medicinal Plants. Paris: Lavoisier Publishing, 1995. DOI
    2. 3741. Larrey D, Vial T, Pauwels A, et al. Hepatitis after germander (Teucrium chamaedrys) administration: another instance of herbal medicine hepatotoxicity. Ann Intern Med 1992;117:129-32.
    3. 3742. Pauwels A, Thierman-Duffaud D, Azanowsky JM, et al. [Acute hepatitis caused by wild germander. Hepatotoxicity of herbal remedies. Two cases]. Gastroenterol Clin Biol 1992;16:92-5.
    4. 3743. Castot A, Djezzar S, Deleau N, et al. [Pharmacovigilance off the beaten track: herbal surveillance or pharmacovigilance of medicinal plants]. Therapie 1997;52:97-103.
    5. 3744. Mostefa-Kara N, Pauwels A, Pines E, et al. Fatal hepatitis after herbal tea. Lancet 1992;340:674. DOI

    Metformin

    Listed in the ADVERSE REACTIONS section of the FDA label for Metformin. Read the label on DailyMed ›

Effects for Metformin come from the ADVERSE REACTIONS section of its FDA label; effects for Germander come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Germander in Pregnancy & Breastfeeding

Pregnancy And Lactation Likely Unsafe

When used orally.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

From our Q&A

Questions About Germander or Metformin

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Germander or Metformin, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Metformin

This page covers Germander only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Metformin page lists 258 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 · 39 minor.

From our pharmacist’s overview on the Metformin page

“Siberian cocklebur is the ingredient I most want anyone taking metformin (Glucophage) to know about. It has caused severe low blood sugar in people, documented in humans, and it should not be combined with any glucose-lowering medication.”

Reviewed by 2 · Jul 18, 2026

Open the Metformin interaction page

How much people look this up

Where Germander and 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 Germander
Steady interest

#1,218 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Metformin
Top 1%

#29 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.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Germander reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Germander and Metformin records this page draws on were last updated July 10, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Germander

What is Germander?

  • Weight loss aids
  • Digestive complaints
  • Appetite stimulation
  • Gout and arthritis (traditional)
  • Fever and infections (traditional)

Germander is a traditional herb that was once used for weight loss and digestion, but it has been linked to serious and sometimes fatal liver damage. Because of these well-documented liver risks, germander has been banned or restricted in several countries, and we strongly advise against using it.

Teucrium chamaedrys · Lamiaceae · Above-ground parts (leaves and flowering tops) · Tea, capsules, tinctures, dried herb

An interaction check asks whether these two react with each other — it does not ask whether Germander is a good idea for someone in your situation. Here is what our Germander record says about it on its own.

Germander: dosing

There is no safe or established dose for germander. A safer, evidence-based option is almost always available.

From our Germander monograph — the full record covers uses, side effects and every documented interaction.

Read the full Germander monograph & all interactions
Medication

About Metformin

What Is Metformin Used For?

Brand names: Glucophage, Metformin

Metformin is used to improve blood sugar (glucose) control in people with type 2 diabetes mellitus. It is always used together with diet and exercise, not instead of them.

Metformin hydrochloride tablets and oral solution are approved for adults and children 10 years and older. Metformin hydrochloride extended-release tablets — including brands such as Fortamet, Glumetza, and Metformin Hydrochloride Extended Release — are approved for adults only.

See full Metformin drug information
Keep checking

Other Drugs & Germander

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

0Major
0Moderate
0Minor
2,829No known interaction
2,829 No interaction
No interaction 2,829 drugs checked — show the list

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

Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Germander list.

See the full Germander interactions page
See every supplement checked against Metformin, ranked by severity
Evidence & sources

Germander References

The 5 references that drive our Germander monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. Bruneton J. Pharmacognosy, Phytochemistry, Medicinal Plants. Paris: Lavoisier Publishing, 1995. DOI
  2. Larrey D, Vial T, Pauwels A, et al. Hepatitis after germander (Teucrium chamaedrys) administration: another instance of herbal medicine hepatotoxicity. Ann Intern Med 1992;117:129-32.
  3. Pauwels A, Thierman-Duffaud D, Azanowsky JM, et al. [Acute hepatitis caused by wild germander. Hepatotoxicity of herbal remedies. Two cases]. Gastroenterol Clin Biol 1992;16:92-5.
  4. Castot A, Djezzar S, Deleau N, et al. [Pharmacovigilance off the beaten track: herbal surveillance or pharmacovigilance of medicinal plants]. Therapie 1997;52:97-103.
  5. Mostefa-Kara N, Pauwels A, Pines E, et al. Fatal hepatitis after herbal tea. Lancet 1992;340:674. DOI

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Germander and Metformin Together: Common Questions

Is it safe to take Germander with Metformin?
We do not list a known interaction between Germander and Metformin. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Do Germander and Metformin have any of the same side effects?
Yes — our sources link each of them separately to one of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
Does Metformin interact with any supplements?
Yes. Metformin has documented interactions with 258 supplements in our database — Germander is not one of them. The Metformin interaction page linked on this page lists every one, ranked by severity.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Where next

Keep Exploring

Germander monograph Uses, safety profile, and every drug interaction in one place Metformin drug information The full plain-English guide to this medication Metformin supplement interactions Every supplement checked against 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 References The 5 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Metformin and Germander?

Our pharmacists answer your medication & supplement questions — free.

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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.