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Dietary supplement

Horse Chestnut Extract Ingredients & Drug Interactions

by 21st Century

Horse Chestnut Extract label
See full label image
Capsule 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 Horse Chestnut Extract 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

Horse Chestnut Extract is a dietary supplement by 21st Century with 1 active ingredient. Its ingredients are commonly taken for chronic venous insufficiency, leg swelling and heaviness, varicose veins.Based on those ingredients, 122 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Horse Chestnut 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 Horse Chestnut Extract by 21st Century

Ask about any prescription or over-the-counter medication and we check it for interactions with Horse Chestnut Extract by 21st Century — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Horse Chestnut Extract by 21st Century

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.

This product contains one active ingredient: horse chestnut extract, which comes from the seeds of the horse chestnut tree. The extract has been processed to remove esculin, a toxic compound found in raw plant parts.

The capsule also contains several inactive ingredients—cellulose, rice bran, oat fiber, maltodextrin, and magnesium silicate—that help deliver the extract.

Does it work?

Moderate evidence
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
Moderate

Some clinical evidence supports this product's ingredients for its stated purpose, but it isn't conclusive.

Why this rating?
  • The label markets this product for: venous circulation and leg health.
  • We looked for evidence on: Chronic venous insufficiency (CVI), Hemorrhoids, Postoperative swelling, varicose veins, leg edema, venous insufficiency.
  • The strongest evidence on file: Horse Chestnut is rated "Possibly Effective" for Chronic venous insufficiency (CVI) (Natural Medicines).
  • Also on file: Horse Chestnut is rated "Insufficient Reliable Evidence To Rate" for Hemorrhoids, Postoperative swelling.

Horse chestnut extract is possibly effective for chronic venous insufficiency (CVI)—a condition where blood doesn't return efficiently from the legs to the heart, causing swelling and discomfort. For hemorrhoids, irritable bowel syndrome, and kidney stones, there isn't enough reliable evidence in our data to say whether it works.

The evidence, ingredient by ingredient Horse Chestnut

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.

The properly processed seed extract in this product is generally well tolerated when taken by mouth, though some people report dizziness, stomach upset, headache, or itching. Raw horse chestnut plant parts are toxic and should never be used.

During pregnancy, there isn't enough safety information, so the data advises against it. Breastfeeding mothers should also avoid it, since safety hasn't been established.

One rare case of a serious heart condition (pericardial effusion) was reported in someone who consumed large amounts of horse chestnut paste, though a direct link wasn't confirmed.

Side effects, ingredient by ingredient Horse Chestnut

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 — Horse Chestnut.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs.
  • For scale: 122 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 you take this product, check with your doctor or pharmacist if you're on any blood thinners (anticoagulants like warfarin) or antiplatelet drugs (like aspirin, clopidogrel, or ticlopidine). Horse chestnut may increase your bleeding risk when combined with these medications.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with some supporting evidence for its stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.

Horse chestnut extract may help with chronic venous insufficiency if you don't take blood thinners or antiplatelet drugs. If you're on any anticoagulant or antiplatelet medication, check with your doctor or pharmacist before starting.

It's not recommended during pregnancy or while breastfeeding. Talk it over with your own healthcare provider to see if it's right 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 23, 2019.

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 Horse Chestnut Extract, straight from the product label.

Brand 21st Century
Barcode (UPC) 740985217818
Net contents 60 Vegetarian Capsule(s)
Market status On market
Date entered into DSLD Aug 23, 2019
DSLD ID 205825
Product type Botanical
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Vegetarian, 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 Horse Chestnut Extract by 21st Century, 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:
2 Vegetarian Capsule(s)
Maximum serving Sizes:
2 Vegetarian Capsule(s)
Servings per container
30
UPC/BARCODE
740985217818
IngredientAmount% DV
Horse Chestnut extract600 mg--

Other ingredients: Cellulose, Rice Bran, Oat Fiber, Maltodextrin, Magnesium Silicate, Contains <2% of

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.
Suggested/Recommended/Usage/Directions

Directions: As a herbal supplement, adults take two (2) capsules daily with any meal or as directed by a healthcare provider. Do not exceed recommended dosage.

Precautions

Do not exceed recommended dosage.

Warning: Consult a healthcare provider prior to use if pregnant, nursing, on medications, have a medical condition or are planning a medical procedure.

Stop use and contact a physician if adverse reactions occur.

Keep out of reach of children.

Do not use if product appears to be tampered with or seal is broken.

General Statements

Individuals results may vary.

Standardized Circulation Support

Storage

Store at room temperature.

Formulation

No added Sugar, Salt, Yeast, Preservatives or Artificial Flavors.

100% Vegetarian.

Gluten free

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.

FDA Statement of Identity

Herbal Supplement

Seals/Symbols

Gluten free

Guaranteed quality Laboratory tested

Formula

Horse Chestnut Extract (Aesculus hippocastanum) has been used for centuries to help support normal circulation in the legs.

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

See for yourself

Horse Chestnut Extract by 21st Century label

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

Horse Chestnut Extract 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 Horse Chestnut Extract by 21st Century

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

Serving size2 Vegetarian Capsule(s) Dosage formCapsule Servings per container30 Amounts shown are per serving.

Horse Chestnut extract

Interacts with
122 drugs
600 mg per serving Form: Aesculus hippocastanum

Horse chestnut seed extract is most often used for chronic venous insufficiency, where standardized products may help reduce leg swelling, pain, and h...

Horse Chestnut extract monograph & interactions

Other (inactive) ingredients: Cellulose, Rice Bran, Oat Fiber, Maltodextrin, Magnesium Silicate, Contains <2% of. These complete the product’s ingredient list but are not active constituents.

Interaction report

Horse Chestnut Extract by 21st Century Drug Interactions

Want to check YOUR meds against Horse Chestnut Extract?

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
122Drugs
122 Moderate

Ingredients driving the most interactions

Horse Chestnut extract 122

Individual Drug Interactions

The ingredients in Horse Chestnut Extract interact with 122 drugs. Click any drug to see the details.

1 of the 1 ingredient in Horse Chestnut Extract interact with drugs. Each result below shows which ingredient is responsible. Horse Chestnut extract

Each ingredient & the kinds of drugs it affects

For each ingredient in Horse Chestnut Extract 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.

Horse Chestnut extract1 drug type · 122 drugs

Anticoagulant/Antiplatelet Drugs

Horse chestnut may have antiplatelet effects and may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Horse chestnut contains the constituent esculin which has been shown to have antithrombotic effects. Therefore, horse chestnut might have antiplatelet effects. This has not been shown in humans.

Likelihood Possible Evidence D
Horse Chestnut extract full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Horse Chestnut Extract, from the product label.

21st Century

See all 21st Century products
Name
21st Century HealthCare, Inc.
Street Address
2119 S. Wilson St.
City
Tempe
State
AZ
ZipCode
85282
Web Address
www.21stcenturyvitamins.com
Pharmacist Counseling Corner

Horse Chestnut Extract by 21st Century: Common Questions

Does Horse Chestnut Extract by 21st Century interact with any medications?
Yes. Based on its ingredients, Horse Chestnut Extract has a known interaction with 122 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Horse Chestnut Extract 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. There isn't enough safety information during pregnancy, so the data advises against it. Breastfeeding safety also hasn't been established, so avoid it while nursing. Talk with your doctor or pharmacist if you have questions about alternatives.
What side effects might I experience?
The most common ones reported are dizziness, stomach upset, headache, and itching. A thorough safety evaluation hasn't been done, so other effects may exist. If you notice anything unusual, stop and tell your pharmacist or doctor.
Does it actually work for varicose veins or swelling in the legs?
It's possibly effective for chronic venous insufficiency—a condition where blood doesn't return well from the legs, causing swelling and heaviness. That's the main use it's studied for. If you have varicose veins or leg swelling, ask your doctor whether this supplement makes sense for you.
Why does the label say the product is processed to remove esculin?
Esculin is a toxic compound found naturally in raw horse chestnut seeds and other plant parts. The extract used here is processed to remove it, making it safe for oral use. Raw horse chestnut should never be taken by mouth.
Is this the same as applying horse chestnut topically?
No—this is an oral capsule, not a cream or lotion. Topical horse chestnut products haven't reported adverse effects in the data we hold, but they're different forms and may be used for different reasons. Ask your pharmacist which form might work best for you.

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.

Horse Chestnut Extract label
Go deeper

The Full Monographs Behind Horse Chestnut Extract’s Ingredients

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

Herb & supplement monograph

Horse Chestnut

Interacts with 122 drugs

Horse chestnut seed extract is most often used for chronic venous insufficiency, where standardized products may help reduce leg swelling, pain, and heaviness. Raw, unprocessed horse chestnu...

Read the full Horse Chestnut monograph →
Sources

Sources & How We Checked

Horse Chestnut Extract'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 21 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.

Horse Chestnut 21 references
  1. Blumenthal M, ed. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Trans. S. Klein. Boston, MA: American Botanical Council, 1998.
  2. Ellenhorn MJ, et al. Ellenhorn's Medical Toxicology: Diagnoses and Treatment of Human Poisoning. 2nd ed. Baltimore, MD: Williams & Wilkins, 1997.
  3. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
  4. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  5. Greeske K, Pohlmann BK. Horse chestnut seed extract-an effective therapy principle in general practice. Drug therapy of chronic venous insufficiency. Fortschr Med 1996;114:196-200.
  6. Robbers JE, Tyler VE. Tyler's Herbs of Choice: The Therapeutic Use of Phytomedicinals. New York, NY: The Haworth Herbal Press, 1999.
  7. Takegoshi K, Tohyama T, Okuda K, et al. A case of Venoplant-induced hepatic injury. Gastroenterol Jpn 1986;21:62-5.
  8. Jaspersen-Schib R, Theus L, Guirguis-Oeschger M, et al. [Serious plant poisonings in Switzerland 1966-1994. Case analysis from the Swiss Toxicology Information Center]. Schweiz Med Wochenschr 1996;126:1085-98.
  9. Popp W, Horak F, Jager S, et al. Horse chestnut (Aesculus hippocastanum) pollen: a frequent cause of allergic sensitization in urban children. Allergy 1992;47:380-3.
  10. Diaz-Perales A, Collada C, Blanco C, et al. Cross-reactions in the latex-fruit syndrome: A relevant role of chitinases but not of complex asparagine-linked glycans. J Allergy Clin Immunol 1999;104:681-7. PubMed
  11. Blanco C, Diaz-Perales A, Collada C, et al. Class I chitinases as potential panallergens involved in the latex-fruit syndrome. J Allergy Clin Immunol 1999;103:507-13. PubMed
  12. Comaish JS, Kersey PJ. Contact dermatitis to extract of horse chestnut (esculin). Contact Dermatitis 1980;6:150-1. PubMed
  13. Pittler MH, Ernst E. Horse chestnut seed extract for chronic venous insufficiency (Cochrane Review). In: The Cochrane Library, Issue 3, 2004. Chichester, UK: John Wiley & Sons, Ltd. PubMed
  14. Ottillinger, B. and Greeske, K. Rational therapy of chronic venous insufficiency--chances and limits of the therapeutic use of horse-chestnut seeds extract. BMC.Cardiovasc.Disord. 2001;1(1):5. PubMed
  15. Pittler, M. H. and Ernst, E. Horse chestnut seed extract for chronic venous insufficiency. Cochrane.Database.Syst.Rev. 2004;(2):CD003230. PubMed
  16. Fang, Y., Zhao, L., Yan, F., Xia, X., Xu, D., and Cui, X. Escin improves sperm quality in male patients with varicocele-associated infertility. Phytomedicine. 2010;17(3-4):192-196. PubMed
  17. De Smet, P. A., Van den Eertwegh, A. J., Lesterhuis, W., and Stricker, B. H. Hepatotoxicity associated with herbal tablets. BMJ 7-13-1996;313(7049):92.
  18. Rehn, D., Unkauf, M., Klein, P., Jost, V., and Lucker, P. W. Comparative clinical efficacy and tolerability of oxerutins and horse chestnut extract in patients with chronic venous insufficiency. Arzneimittelforschung 1996;46(5):483-487.
  19. Edem E, Kahyaoglu B, Çakar MA. Acute Effusive Pericarditis due to Horse Chestnut Consumption. Am J Case Rep. 2016;17:305-8. PubMed
  20. Costa Santos D, Lérias G, Madruga I. Drug-induced Liver Injury Due to a Horse Chestnut Dietary Supplement. Eur J Case Rep Intern Med 2021;8(3):002389. PubMed
  21. Yi HY, Lee JY. Poisoning due to consumption of horse chestnut seed. Clin Exp Emerg Med 2021;8(4):333-335. PubMed

See these in context on the Horse Chestnut 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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