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Dietary supplement

Horsetail Alcohol Free Ingredients & Drug Interactions

by Hawaii Pharm

Horsetail Alcohol Free 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 Horsetail Alcohol Free 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

Horsetail Alcohol Free 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 Horsetail Herb Extract, Dry. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Horsetail Alcohol Free by Hawaii Pharm

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

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HelloPharmacist Scorecard of Horsetail Alcohol Free 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 Aug 6, 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.

Horsetail Alcohol Free contains one active ingredient: a dry extract of horsetail herb. The liquid formulation also includes glycerin and water 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 for horsetail is sparse. Our data shows insufficient reliable evidence to rate it for urinary incontinence, weight loss, throat infections (tonsillitis), or male-pattern hair loss (androgenic alopecia).

That doesn't mean it doesn't work—it means the clinical evidence hasn't been established yet.

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 can be used short-term by healthy adults, but long-term use carries real risks and unverified products are a concern. The most common side effects reported are abdominal bloating, increased bowel movements, and nausea.

Crude horsetail can contain thiaminase, an enzyme that depletes thiamine (vitamin B1) with prolonged use; products made in Canada are required to be tested and certified as free from this risk. One person developed a skin reaction (seborrheic dermatitis) after applying horsetail topically, traced to its nicotine content.

There isn't enough safety data to use horsetail during pregnancy or while breastfeeding; the data advises against it in both cases.

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.

Check with your doctor or pharmacist before taking this product if you're on antiretroviral drugs (NRTIs or efavirenz), antidiabetes medications, diuretics, or lithium. Horsetail may reduce the effectiveness of HIV medications, lower your blood sugar, increase potassium loss, or raise lithium levels in your blood.

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.

Horsetail might be worth trying short-term for specific uses if you're a healthy adult, but the evidence for it is weak and side effects are possible. It's a serious concern if you take antiretroviral drugs, diabetes or blood pressure medications, diuretics, or lithium.

Talk with your doctor or pharmacist before starting—they'll know your full medication list and can tell you whether it's a fit for you.

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 Aug 24, 2023.

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 Horsetail Alcohol Free, straight from the product label.

Brand Hawaii Pharm
Barcode (UPC) 840253627940
Net contents 4 Fluid Ounce(s); 120 mL
Market status On market
Date entered into DSLD Aug 24, 2023
DSLD ID 300832
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 Horsetail Alcohol Free 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
840253627940
IngredientAmount% DV
Horsetail Herb Extract, Dry1156 mg--

Other ingredients: Glycerin, Water

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.
Brand IP Statement(s)

Hawaii Pharm Herbal Extract Highest quality since 2008

Suggested/Recommended/Usage/Directions

Suggested use: Shake well before using. For adults add about 20-30 drops (0.7-1 mL, one full squeeze of the dropper bulb) to some juice or water, up to 4 times a day.

Precautions

Warning: We recommend to seek expert medical advice before taking.

Do not use if you are allergic to any ingredients.

Consult your physician before giving to children under 18, during pregnancy, if nursing or taking medications.

Consult your physician before giving to children under 18, during pregnancy, if nursing or taking medications.

May affect the ability to drive and operate machinery. May have contraindications, can cause side effects and adverse reactions. Do not use if seal is broken or missing.

Keep out of the reach of children!

Storage

Store in a cool dry place.

Seals/Symbols

cGMP Made in compliance with cGMP 21 CFR 111 in an FDA registered and inspected facility.

C2H5OH Alcohol free USA Made in United States of America

FDA Disclaimer Statement

This product has not been evaluated by the FDA and is not intended to diagnose, treat, cure or prevent any disease.

General Statements

Scan this QR-code to get 15% discount on your next purchase. Limited time deal.

Formula

Equisetum arvense

Formulation

Only natural ingredients Purity is laboratory tested and verified

All the raw materials are gluten-free by their nature No artificial colors, flavors, or preservatives

Not tested on animals

C2H5OH Alcohol free

Made in USA, Hawaii

FDA Statement of Identity

Herbal Supplement

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

See for yourself

Horsetail Alcohol Free by Hawaii Pharm label

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

Horsetail Alcohol Free 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 Horsetail Alcohol Free 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.

Horsetail Herb Extract, Dry

Interacts with
188 drugs
1156 mg per serving Form: Equisetum arvense Herb Extract, Dry

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...

Horsetail Herb Extract, Dry monograph & interactions

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

Interaction report

Horsetail Alcohol Free by Hawaii Pharm Drug Interactions

Want to check YOUR meds against Horsetail Alcohol Free?

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

Horsetail Herb Extract, Dry 188

Individual Drug Interactions

The ingredients in Horsetail Alcohol Free interact with 188 drugs. Click any drug to see the details.

1 of the 1 ingredient in Horsetail Alcohol Free interact with drugs. Each result below shows which ingredient is responsible. Horsetail Herb Extract, Dry

Each ingredient & the kinds of drugs it affects

For each ingredient in Horsetail Alcohol Free 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.

Horsetail Herb Extract, Dry5 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
Horsetail Herb Extract, Dry full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Horsetail Alcohol Free, from the product label.

Hawaii Pharm

See all Hawaii Pharm products
Name
Hawaii Pharm LLC
Street Address
510 Sumner St. Ste. 613
City
Honolulu
State
HI
ZipCode
96817
Phone Number
888-854-2924
Web Address
www.hawaiipharm.com
Pharmacist Counseling Corner

Horsetail Alcohol Free by Hawaii Pharm: Common Questions

Does Horsetail Alcohol Free by Hawaii Pharm interact with any medications?
Yes. Based on its ingredients, Horsetail Alcohol Free 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?
Horsetail Alcohol Free 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 while pregnant or breastfeeding?
No. The safety data advises against horsetail during pregnancy and while breastfeeding. If you're pregnant, planning to become pregnant, or nursing, talk with your doctor or pharmacist before taking any horsetail product.
What are the side effects?
The most common ones are abdominal bloating, increased bowel movements, and nausea. Horsetail can also deplete thiamine (a B vitamin) if used long-term, though Canadian products are tested to be free from this risk. One person had a skin reaction to topical horsetail.
Does horsetail actually work for anything?
The evidence isn't established yet. Our data shows insufficient reliable evidence to rate it for urinary incontinence, weight loss, throat infections, or hair loss—so we can't tell you whether it works for those uses.
How long can I safely take this?
It may be used short-term by healthy adults, but long-term use carries real risks. Talk with your doctor or pharmacist about how long is safe for you.
What if I'm taking diuretics or blood pressure medication?
Horsetail also acts as a diuretic, so it may increase potassium loss if you're on potassium-depleting diuretics. Check with your doctor or pharmacist before adding it—your medication dose or type might need to change.
Is this product thiaminase-free?
If it's manufactured in Canada, the product is required by law to be certified as free from thiaminase-like activity. Products from other countries may not carry this assurance. Check the label or ask the manufacturer.

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.

Horsetail Alcohol Free label
Go deeper

The Full Monographs Behind Horsetail Alcohol Free’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

Horsetail Alcohol Free'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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