Drug & supplement interaction

Horsetail + Repaglinide

Repaglinide brand names: Prandin, GlucoNorm.

Moderate Interaction
The bottom line Moderate

Horsetail has a moderate interaction with Repaglinide. Theoretically, taking horsetail with antidiabetes drugs might increase the risk of hypoglycemia.

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

Horsetail 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 Horsetail interacts with.

Theoretically, taking horsetail with antidiabetes drugs might increase the risk of hypoglycemia.
Equisetum myriochaetum has demonstrated hypoglycemic activity in clinical research. In an animal diabetic model, Equisetum giganteum had hypoglycemic effects. It is unclear whether other horsetail species have hypoglycemic effects.
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

Repaglinide works by nudging your pancreas to release more insulin, which lowers your blood sugar. Some horsetail species have shown blood-sugar-lowering activity in lab and animal studies, so the concern here is simple: if horsetail also pushes your sugar down a little, stacking it on top of repaglinide could add up and drop your glucose too low.

I want to be upfront that this is a theoretical worry based on pharmacology, not strong human proof. Still, if you take both, keep an eye out for low blood sugar signs like shakiness, sweating, dizziness, or confusion, and check your readings more closely. Don't change anything on your own. Loop in your pharmacist or doctor first so they can guide you safely.

References
  1. Revilla MC, Andrade-Cetto A, Islas S, Wiedenfeld H. Hypoglycemic effect of Equisetum myriochaetum aerial parts on type 2 diabetic patients. J Ethnopharmacol 2002;81:117-20. PubMed
  2. Vieira GT, de Oliveira TT, Carneiro MAA, et al. Antidiabetic effect of Equisetum giganteum L. extract on alloxan-diabetic rabbit. J Ethnopharmacol. 2020;260:112898. 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

Horsetail Also Interacts With Other Medications

Horsetail has 187 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 Horsetail

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

From our Q&A

Questions About Horsetail or Repaglinide

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Horsetail or Repaglinide, 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 Repaglinide

This page covers Horsetail 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

One more smart check

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

We hold 2,089 real supplement products containing Horsetail, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Horsetail. Your product may carry other ingredients that interact with Repaglinide too, on top of Horsetail — 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 Horsetail 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 Horsetail
Top 10%

#137 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 Horsetail

What is Horsetail?

Horsetail
  • Fluid retention (mild diuretic)
  • Urinary and bladder concerns
  • Hair, skin, and nail support
  • Wound healing
  • Bone health

Horsetail is a traditional herb most often used as a mild diuretic and for hair, nail, and bone support, but high-quality human evidence is limited. It can cause thiamine (vitamin B1) loss with long-term use, and some related species are toxic, so choose products carefully and talk to your pharmacist or doctor before using it.

Read the full Horsetail 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 & Horsetail

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

0Major
187Moderate
0Minor
2,642No known interaction
Moderate

187 interactions

Showing 60 of 187 moderate interactions — see all 187 on the Horsetail page.

No interaction 2,642 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 Horsetail and Repaglinide Together: Common Questions

Can you take Horsetail 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 Horsetail 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 Horsetail?

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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.