Drug & supplement interaction

White Horehound + Repaglinide

Repaglinide brand names: Prandin, GlucoNorm.

Moderate Interaction
The bottom line Moderate

White Horehound has a moderate interaction with Repaglinide. Evidence from animal research suggests that white horehound might lower blood glucose.

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

White Horehound and Repaglinide

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

Moderate

ANTIDIABETES DRUGS

Why this applies to Repaglinide

Repaglinide falls under ANTIDIABETES DRUGS — the group White Horehound interacts with.

Evidence from animal research suggests that white horehound might lower blood glucose. However, preliminary clinical research suggests that white horehound only slightly lowers blood glucose when taken in combination with antidiabetic agents, suggesting that the effect may not be clinically significant. Until more is known, use with caution. Theoretically, white horehound may have additive effects when used by patients taking antidiabetic drugs. The dose of diabetes medications might need to be adjusted. 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 B

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: repaglinide already works by nudging your pancreas to release more insulin, which brings your blood sugar down. White horehound has been studied a bit for its own mild sugar-lowering effect, so the worry is that the two together could push your blood sugar a little lower than you intend. If that happens, you might notice the usual signs of low blood sugar (hypoglycemia), like shakiness, sweating, dizziness, a racing heart, or feeling suddenly hungry or foggy.

Now, the honest part: the human evidence here is weak, and the studies suggest horehound only slightly lowers blood sugar, so this may not amount to much for most people. An occasional horehound cough drop is very unlikely to matter. If you're using concentrated supplement doses, just keep an eye on your readings and check in with your pharmacist or doctor before changing anything.

References
  1. Roman, Ramos R., Alarcon-Aguilar, F., Lara-Lemus, A., and Flores-Saenz, J. L. Hypoglycemic effect of plants used in Mexico as antidiabetics. Arch.Med.Res 1992;23:59-64.
  2. Novaes AP, Rossi C, Poffo C, et al. Preliminary evaluation of the hypoglycemic effect of some Brazilian medicinal plants. Therapie. 2001;56(4):427-30.
  3. Herrera-Arellano, A., Aguilar-Santamaria, L., Garcia-Hernandez, B., Nicasio-Torres, P., and Tortoriello, J. Clinical trial of Cecropia obtusifolia and Marrubium vulgare leaf extracts on blood glucose and serum lipids in type 2 diabetics. Phytomedicine 200 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

White Horehound Also Interacts With Other Medications

White Horehound has 257 moderate known drug interactions in our database — the Repaglinide 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 White Horehound

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

Everything else you take

See Every Supplement That Interacts With Repaglinide

This page covers White Horehound only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Repaglinide page lists 256 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 · 215 moderate · 39 minor.

From our pharmacist’s overview on the Repaglinide page

“Repaglinide (Prandin, GlucoNorm) is taken right before meals to drop blood sugar quickly, and that speed is exactly why this list deserves real respect. Nearly everything on it also acts on blood sugar, usually pushing it lower still and raising the odds of a hypoglycemic crash, though a handful, niacin among them, pull the other way a…”

Reviewed by 2 · Jul 18, 2026

Open the Repaglinide interaction page

How much people look this up

Where White Horehound and Repaglinide 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 White Horehound
Steady interest

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

29 days ago today
Medication Repaglinide
Top 25%

#400 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 White Horehound

What is White Horehound?

White Horehound
  • Cough and chest congestion
  • Sore throat
  • Bronchitis
  • Digestive upset and poor appetite
  • Bloating and gas

White horehound is a traditional bitter herb used mainly for coughs, sore throats, and mild digestive complaints, and it is a common flavoring in old-fashioned cough drops. Solid human evidence supporting these uses is limited, so view it as a folk remedy rather than a proven treatment. Talk to your pharmacist or doctor before using it, and avoid it during pregnancy.

Read the full White Horehound monograph & all interactions
Medication

About Repaglinide

What Is Repaglinide Used For?

Brand names: Prandin, GlucoNorm

Repaglinide tablets are used to help control blood sugar in adults with type 2 diabetes, together with diet and exercise. It is not a substitute for healthy habits — it works best as part of a full diabetes management plan.

Repaglinide is not for type 1 diabetes or for treating diabetic ketoacidosis (a dangerous condition where the blood becomes too acidic due to lack of insulin).

See full Repaglinide drug information
Keep checking

Other Drugs & White Horehound

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

0Major
257Moderate
0Minor
2,572No known interaction
Moderate

257 interactions

Showing 60 of 257 moderate interactions — see all 257 on the White Horehound page.

No interaction 2,572 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 White Horehound and Repaglinide Together: Common Questions

Can you take White Horehound with Repaglinide?
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 White Horehound and Repaglinide 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 Repaglinide and White Horehound?

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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.