Drug & supplement interaction

Horsetail + Insulin (Human)

Insulin (Human) brand names: Novolin N, Novolin 70/30, Novolin R, Novolin L, Afrezza.

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

Horsetail has a moderate interaction with Insulin (Human). 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 Insulin (Human)

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

Moderate

ANTIDIABETES DRUGS

Why this applies to Insulin (Human)

Insulin (Human) 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

Here's the thing to keep an eye on with horsetail and your insulin. Some horsetail species have shown a mild blood-sugar-lowering effect in early research, so combining it with insulin could, in theory, push your sugar a little lower than you'd expect. Since insulin already works hard to bring blood sugar down, stacking another sugar-lowering effect on top might raise your odds of a low (hypoglycemia), with signs like shakiness, sweating, dizziness, a racing heart, or confusion.

I want to be honest that this concern is mostly theoretical, based on lab and animal studies rather than strong human data. Still, if you'd like to use horsetail, check in with your pharmacist or doctor first and watch your glucose readings a bit more closely at the start.

Contact Dr. Brian directly if you have additional questions on this interaction
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 Insulin (Human) one above is one of them. If you take anything else, check it against the full list below.

Moderate 187 No known interaction 2,643 (incl. Insulin (Human))
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 Insulin (Human)

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 Insulin (Human), 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 Insulin (Human)

This page covers Horsetail only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Insulin (Human) page lists 259 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Chelation Therapy Products (major), Siberian Cocklebur (major), Acai (moderate) and African Wild Potato (moderate).

By severity: 3 major · 218 moderate · 38 minor.

From our pharmacist’s overview on the Insulin (Human) page

“With human insulin (Novolin, Afrezza), extra glucose lowering is not a nuisance, it is the hazard itself, and this is one of the lists I treat as genuinely serious. Nearly every ingredient here either drops blood sugar on its own or adds to insulin's effect, and the combination can push a normal dose into hypoglycemia, a dangerous low.”

Reviewed by 2 · Jul 18, 2026

Open the Insulin (Human) 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 Insulin (Human) 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 Insulin (Human) 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%

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

29 days ago today
Medication Insulin (Human)
Top 10%

#169 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 Human Insulin Injection

What Is Human Insulin Injection Used For?

Brand names: Novolin N, Novolin 70/30, Novolin R, Novolin L, Afrezza

Novolin (human insulin injection) is used to improve glycemic control — meaning blood sugar management — in adults and children with diabetes mellitus.

Novolin 70/30 is a fixed-ratio mixture of intermediate-acting and short-acting human insulin. Because the ratio is fixed, it cannot be adjusted separately for background (basal) or mealtime (prandial) needs.

See full Human Insulin Injection 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
187 Moderate 2,642 No 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

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

Showing the 60 most looked-up of 2,642 medications checked with no known interaction — see the full Horsetail list.

See the full Horsetail interactions page
See every supplement checked against Insulin (Human), 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
Horsetail monograph › Uses, safety, and every drug interaction in one place Insulin (Human) supplement interactions › Every supplement checked against Insulin (Human), ranked by severity Human Insulin Injection drug information › The full plain-English guide to this medication 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 Horsetail and Insulin (Human) Together: Common Questions

Can you take Horsetail with Insulin (Human)?
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 Insulin (Human) 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 Insulin (Human) 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.