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Dietary supplement

Scouring Rush Ingredients & Drug Interactions

by Hawaii Pharm

Scouring Rush label
See full label image
Liquid Category: Botanical
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Scouring Rush against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Moderate

Scouring Rush is a dietary supplement by Hawaii Pharm with 1 active ingredient. Its ingredients are commonly taken for fluid retention (mild diuretic), urinary and bladder concerns, hair, skin, and nail support.Based on those ingredients, 188 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Scouring Rush extract. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Scouring Rush by Hawaii Pharm

Ask about any prescription or over-the-counter medication and we check it for interactions with Scouring Rush by Hawaii Pharm — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Scouring Rush by Hawaii Pharm

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Sep 10, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

This product contains one active ingredient: scouring rush extract, also known as horsetail. The liquid also includes vegetable palm glycerin and alcohol as inactive ingredients.

Does it work?

Couldn't assess
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Not assessable

This is a single-ingredient Horsetail product and its label doesn't state a use — see Horsetail's own graded uses on its monograph.

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.

The evidence we hold for horsetail doesn't clearly support its use for the conditions studied. The data rates it as insufficient reliable evidence for urinary incontinence, obesity, tonsillitis, and androgenic alopecia (male-pattern hair loss).

That means the research so far hasn't been strong enough to say whether it works for these purposes.

The evidence, ingredient by ingredient Horsetail

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 1 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Horsetail is generally well tolerated in the short term for healthy adults, but long-term use and unverified products carry real risks. The most common side effects are abdominal bloating, increased bowel movements, and nausea.

Crude horsetail can contain thiaminase, an enzyme that breaks down thiamine (vitamin B1); prolonged use might deplete this vitamin and cause serious problems. Some horsetail products are certified to be free from thiaminase-like activity.

One rare case report linked a skin reaction to the nicotine in horsetail. There isn't enough safety data to recommend this product during pregnancy or while breastfeeding.

Side effects, ingredient by ingredient Horsetail

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Horsetail.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: diabetes medications; lithium.
  • For scale: 188 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Before taking this product, check with your doctor or pharmacist if you take nucleoside reverse transcriptase inhibitors or efavirenz (HIV medications) — horsetail may lower their levels and reduce how well they work. Also double-check if you're on antidiabetes drugs, diuretics (water pills), or lithium, as all carry Moderate-severity interactions.

Altogether, these interactions span 188 individual medications.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with no assessable stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.

Scouring Rush is not well-studied for any of the conditions it's marketed for. If you take blood sugar medications, water pills, lithium, or HIV antiretrovirals, this product poses real risks — check with your doctor or pharmacist before starting.

Even if you don't take those drugs, talk it over with your healthcare provider, especially if you're thinking of using it long-term.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated Oct 23, 2020.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Scouring Rush, straight from the product label.

Brand Hawaii Pharm
Barcode (UPC) 738600509424
Net contents 4 Fluid Ounce(s); 120 mL
Market status On market
Date entered into DSLD Oct 23, 2020
DSLD ID 237597
Product type Botanical
Supplement form Liquid
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten Free
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Scouring Rush by Hawaii Pharm, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
0.7 mL
Maximum serving Sizes:
1 mL
Servings per container
120
UPC/BARCODE
738600509424
IngredientAmount% DV
Scouring Rush extract970 mg--

Other ingredients: Vegetable Palm Glycerin, Alcohol

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
General Statements

Hawaii Pharm Herbal Extract Highest quality since 2008

Made with Aloha!

Formulation

Contains no GMO, gluten, artificial colors, heavy metals, preservatives, pesticides, fertilizers.

Super concentrated liquid herbal extract. Dry herb/menstruum ratio: 1:3.

Manufactured in an FDA registered facility.

Non GMO Gluten free

Made in USA, Hawaii

Suggested/Recommended/Usage/Directions

Directions for use: Shake well before using. Take about 20-30 drops (0.7-1 ml, one full squeeze of the dropper bulb) to 2-4 oz of juice or water up to 4 times per day.

Precautions

Warning: Keep out of the reach of children.

May have contraindications. We recommend to seek expert medical advice before taking.

Do not use if you are allergic to any ingredients.

Consult a physician before using during pregnancy, if nursing or taking any medications.

Do not use if seal is broken or missing.

Storage

Store in a cool dry place.

Formula

(Equisetum hyemale)

FDA Statement of Identity

Herbal Dietary Supplement

FDA Disclaimer Statement

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.

Seals/Symbols

FDA Registered Facility Made in United States of America USA

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Scouring Rush by Hawaii Pharm label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Scouring Rush label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in Scouring Rush by Hawaii Pharm

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size0.7 mL Dosage formLiquid Servings per container120 Amounts shown are per serving.

Scouring Rush extract

Interacts with
188 drugs
970 mg per serving

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. I...

Scouring Rush extract monograph & interactions

Other (inactive) ingredients: Vegetable Palm Glycerin, Alcohol. These complete the product’s ingredient list but are not active constituents.

Interaction report

Scouring Rush by Hawaii Pharm Drug Interactions

Want to check YOUR meds against Scouring Rush?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
188Drugs
188 Moderate

Ingredients driving the most interactions

Scouring Rush extract 188

Individual Drug Interactions

The ingredients in Scouring Rush interact with 188 drugs. Click any drug to see the details.

1 of the 1 ingredient in Scouring Rush interact with drugs. Each result below shows which ingredient is responsible. Scouring Rush extract

Each ingredient & the kinds of drugs it affects

For each ingredient in Scouring Rush with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.

Scouring Rush extract5 drug types · 188 drugs

Antidiabetes Drugs

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.

Likelihood Possible Evidence D
Diuretic Drugs

Theoretically, taking horsetail with diuretic drugs might increase potassium loss and the risk of hypokalemia.
Laboratory research shows that various species of horsetail have diuretic properties. Due to its diuretic effects, there has been concern that taking horsetail along with potassium-depleting diuretics might increase the risk for hypokalemia. However, pharmacokinetic research in humans shows that taking horsetail 900 mg daily for 4 days does not affect urinary excretion of electrolytes, including potassium and sodium, despite having a diuretic effect similar to taking hydrochlorothiazide 25 mg daily. It is unclear if taking horsetail for a longer duration would affect electrolyte levels. Until more is known, use with caution.

Likelihood Possible Evidence D
Efavirenz (Sustiva)

Theoretically, horsetail might decrease the levels and clinical effects of efavirenz.
In two case reports, patients were found to have detectable viral loads when taking horsetail-containing supplements along with an antiretroviral regimen that included efavirenz. In one case, the antiretroviral regimen included zidovudine, lamivudine, and efavirenz; in the other case, the regimen consisted of emtricitabine, tenofovir disoproxil fumarate, and efavirenz. One month after discontinuing horsetail, the viral loads became undetectable in both cases. The exact mechanism of this interaction is unknown. It is also unclear if this interaction is specific to efavirenz or if it is related to various components of antiretroviral therapy.

Likelihood Possible Evidence D
Lithium

Theoretically, horsetail might increase the levels and adverse effects of lithium.
Animal research suggests that horsetail has diuretic properties. Theoretically, due to these potential diuretic effects, horsetail might reduce excretion and increase levels of lithium. The dose of lithium might need to be decreased.

Likelihood Possible Evidence D
Nucleoside Reverse Transcriptase Inhibitors (Nrtis)

Theoretically, horsetail might decrease the levels and clinical effects of NRTIs.
In two case reports, patients were found to have detectable viral loads when taking horsetail-containing supplements along with an antiretroviral therapy. In one case, the antiretroviral regimen included zidovudine, lamivudine, and efavirenz; in the other case, the regimen consisted of emtricitabine, tenofovir disoproxil fumarate, and efavirenz. One month after discontinuing the supplement, the viral loads became undetectable in both cases. The exact mechanism of these interactions is unknown. It is also unclear if these interactions are specific to NRTIs or if they are related to various components of antiretroviral therapy.

Likelihood Possible Evidence D
Scouring Rush extract full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Scouring Rush, from the product label.

Hawaii Pharm

See all Hawaii Pharm products
Name
Hawaii Pharm LLC
City
Honolulu
State
HI
ZipCode
96815
Web Address
www.hawaiipharm.com
Pharmacist Counseling Corner

Scouring Rush by Hawaii Pharm: Common Questions

Does Scouring Rush by Hawaii Pharm interact with any medications?
Yes. Based on its ingredients, Scouring Rush has a known interaction with 188 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Scouring Rush contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Can I take this if I'm pregnant or breastfeeding?
There isn't enough safety data on horsetail to know if it's safe in pregnancy or while breastfeeding. The safety data we hold advises against it during both. Talk with your doctor or pharmacist about your specific situation before taking it.
What are the most common side effects?
The most common ones reported are belly bloating, increased bowel movements, and nausea. Long-term use of crude horsetail can also deplete thiamine (vitamin B1), which can cause serious problems. Some products are certified thiaminase-free — look for that if you're considering long-term use.
Does this actually work for what it claims?
The evidence we hold rates horsetail as insufficient to say whether it works for urinary incontinence, obesity, tonsillitis, or hair loss. The research hasn't been strong enough yet to confirm any of these uses.
Why does this interact with so many drugs?
Horsetail has diuretic effects — meaning it increases urine output — and may lower blood sugar. These properties can change how your body handles certain medications, including how your kidneys filter lithium and how your liver processes some HIV drugs. That's why it affects multiple drug types.
Is it safe to use long-term?
The safety data we hold cautions that while horsetail may be used short-term by healthy adults, long-term use carries real risks — chiefly thiamine deficiency if it's not certified thiaminase-free. Talk with your doctor about how long you're planning to take it.

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

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Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

Scouring Rush label
Go deeper

The Full Monographs Behind Scouring Rush’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Horsetail

Interacts with 188 drugs

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 w...

Read the full Horsetail monograph →
Sources

Sources & How We Checked

Scouring Rush's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 14 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Horsetail 14 references
  1. Sudan BJ. Seborrhoeic dermatitis induced by nicotine of horsetails (Equisetum arvense L.). Contact Dermatitis 1985;13:201-2.
  2. Perez Gutierrez RM, Laguna GY, Walkowski A. Diuretic activity of Mexican equisetum. J Ethnopharmacol 1985;14:269-72. PubMed
  3. Lemus I, Garcia R, Erazo S, et al. Diuretic activity of an Equisetum bogotense tea (Platero herb): evaluation in healthy volunteers. J Ethnopharmacol 1996;54:55-8. PubMed
  4. 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
  5. Tiktinskii, O. L. and Bablumian, I. A. [Therapeutic action of Java tea and field horsetail in uric acid diathesis]. Urol.Nefrol.(Mosk) 1983;3(1):47-50.
  6. Henderson JA, Evans EV, and McIntosh RA. The antithiamine action of Equisetum. J Amer Vet Med Assoc 1952;120:375-378.
  7. Carneiro DM, Freire RC, Honório TC, Zoghaib I, Cardoso FF, Tresvenzol LM, de Paula JR, Sousa AL, Jardim PC, da Cunha LC. Randomized, Double-Blind Clinical Trial to Assess the Acute Diuretic Effect of Equisetum arvense (Field Horsetail) in Healthy Voluntee
  8. Klnçalp S, Ekiz F, Basar Ö, Coban S, Yüksel O. Equisetum arvense (Field Horsetail)-induced liver injury. Eur J Gastroenterol Hepatol. 2012 Feb;24(2):213-4. PubMed
  9. Ortega García JA, Angulo MG, Sobrino-Najul EJ, Soldin OP, Mira AP, Martínez-Salcedo E, Claudio L. Prenatal exposure of a girl with autism spectrum disorder to 'horsetail' (Equisetum arvense) herbal remedy and alcohol: a case report. J Med Case Rep. 2011 M PubMed
  10. Cordova E, Morganti L, Rodriguez C. Possible Drug-Herb Interaction between Herbal Supplement Containing Horsetail (Equisetum arvense) and Antiretroviral Drugs. J Int Assoc Provid AIDS Care. 2017;16(1):11-13.
  11. García Gavilán MD, Moreno García AM, Rosales Zabal JM, Navarro Jarabo JM, Sánchez Cantos A. Case of drug-induced acute pancreatitis produced by horsetail infusions. Rev Esp Enferm Dig. 2017 Apr;109(4):301-304. PubMed
  12. 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
  13. Health Canada. Organism-Equisetum arvense. Available at: http://webprod.hc-sc.gc.ca/nhpid-bdipsn/ingredReq.do?id=6117&lang=eng. Accessed 21-July 2021.
  14. Bates D, Duong TB, Kheyson S, Moore K. Hyponatremia Secondary to Decreased Oral Intake and SIADH and Possibly Exacerbated by Horsetail (Equisetum arvense). Can J Hosp Pharm 2021;74(4):386-389. PubMed

See these in context on the Horsetail monograph →

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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