Horse Chestnut 

This fact sheet provides basic information about horse chestnut—common 

names, uses, potential side effects, and resources for more information. Horse 

chestnut trees are native to the Balkan Peninsula (for example, Greece and 

Bulgaria), but grow throughout the Northern Hemisphere. Although horse 

chestnut is sometimes called buckeye, it should not be confused with the Ohio 

or California buckeye trees, which are related but not the same species. 

Common Names—horse chestnut, buckeye, Spanish chestnut 

Latin Name—Aesculus hippocastanum 

What It Is Used For 

•	 For centuries, horse chestnut seeds, leaves, bark, and flowers have been 

used for a variety of conditions and diseases. 

•	 Horse chestnut seed extract has been used to treat chronic venous 

insufficiency (a condition in which the veins do not efficiently return 

blood from the legs to the heart). This condition is associated with 

varicose veins, pain, ankle swelling, feelings of heaviness, itching, and 

nighttime leg cramping. 

•	 The seed extract has also been used for hemorrhoids. 

How It Is Used 

Horse chestnut seed extract standardized to contain 16 to 20 percent aescin 

(escin), the active ingredient, is the most commonly used form. Topical 

preparations have also been used. 

What the Science Says 

•	 Small studies have found that horse chestnut seed extract is beneficial in 

treating chronic venous insufficiency and is as effective as wearing 

compression stockings. 

•	 There is not enough scientific evidence to support the use of horse chestnut 

seed, leaf, or bark for any other conditions. 

Side Effects and Cautions 

•	 Homemade preparations of horse chestnut should not be used. Raw horse 

chestnut seeds, leaves, bark, and flowers contain esculin, which is poisonous. 

•	 When properly processed, horse chestnut seed extract contains little or no 

esculin and is considered generally safe. However, the extract can cause 

some side effects, including itching, nausea, or gastrointestinal upset. 
 

•	 Tell your health care providers about any complementary and alternative practices you 

use. Give them a full picture of what you do to manage your health. This will help ensure 

coordinated and safe care. 

Sources 

Horse chestnut. Natural Medicines Comprehensive Database Web site. Accessed at http://www.naturaldatabase.com 

on July 5, 2007. 

Horse chestnut. Natural Standard Database Web site. Accessed at http://www.naturalstandard.com on July 3, 2007. 

Horse chestnut seed extract. In: Blumenthal M, Goldberg A, Brinckman J, eds. Herbal Medicine Expanded Commission E 

Monographs. Newton, MA: Lippincott Williams & Wilkins; 2000:201-204. 

For More Information 

Visit the NCCAM Web site at nccam.nih.gov and view: 

•	 What’s in the Bottle? An Introduction to Dietary Supplements at nccam.nih.gov/health/bottle/ 

•	 Herbal Supplements: Consider Safety, Too at nccam.nih.gov/health/supplement-safety/ 

NCCAM Clearinghouse 

Toll-free in the U.S.: 1-888-644-6226 

TTY (for deaf and hard-of-hearing callers): 1-866-464-3615 

E-mail: info@nccam.nih.gov 

CAM on PubMed 

Web site: nccam.nih.gov/camonpubmed/ 

NIH Office of Dietary Supplements 

Web site: www.ods.od.nih.gov 

NIH National Library of Medicine’s MedlinePlus 

Horse Chestnut Listing: www.nlm.nih.gov/medlineplus/druginfo/natural/patient-horsechestnut.html 

This publication is not copyrighted and is in the public domain. Duplication is encouraged. 

NCCAM has provided this material for your information. It is not intended to substitute 

for the medical expertise and advice of your primary health care provider. We encourage 

you to discuss any decisions about treatment or care with your health care provider. The 

mention of any product, service, or therapy is not an endorsement by NCCAM. 

National Institutes of Health 

♦♦♦

U.S. Department of Health and Human Services 

D321 

Created May 2006 

Updated June 2008 

*D321*