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Horse Chestnut Seed Extract (Aesculus hippocastanum)  

Be aware that the U. S. Food and Drug Administration does not strictly regulate herbs and dietary supplements. There is no guarantee of strength, purity or safety of products containing or claiming to contain valerian. Decisions to use herbs or supplements should be carefully considered. Individuals using prescription drugs should discuss taking herbs or supplements with their pharmacists or health care providers before starting.


Scientists have studied horse chestnut seed extract for the following health problem:

Chronic venous insufficiency
Horse chestnut seed extract is most studied for a condition called chronic venous insufficiency. This term is more common in Europe than the United States. It describes several different problems that may be caused by the failure of lower leg veins to work correctly. These problems include leg swelling (edema), pain, itching, varicose veins, breakdown of skin and skin ulcers. Multiple studies suggest that horse chestnut seed extract may help these problems, possibly as well as other treatments, such as compression stockings. However, these studies are small, low quality and not fully convincing. Better research is necessary to provide a clear answer. If you experience sudden leg swelling, consult your health care provider immediately.

Unproven Uses    

Horse chestnut seed extract has been suggested for many other uses, based on tradition or on scientific theories. However, these uses have not been thoroughly studied in humans, and there is limited scientific evidence about safety or effectiveness. Some of these suggested uses are for conditions that are potentially very serious and even life-threatening. You should consult with a health care provider before using horse chestnut seed extract for any unproven use.

Blood clots
Fluid in the lungs (pulmonary edema)
Gallbladder disease
Kidney disease
Liver disease
Menstrual cramps
Nerve pain (neuropathy)
Nighttime leg cramps
Prostate enlargement (benign prostatic hypertrophy)
Rectal irritation
Rheumatoid arthritis
Ringing in the ears (tinnitus)
Stomach ulcers
Varicose leg ulcers
Whooping cough (pertussis)

Potential Dangers    


Side Effects

Pregnancy And Breast-Feeding


Interactions with drugs, supplements and other herbs have not been thoroughly studied. The interactions listed below have been reported in scientific publications. If you are taking prescription drugs, speak with your health care provider or pharmacist before using herbs or dietary supplements.

Interactions With Drugs

Interactions With Herbs And Dietary Supplements


The doses listed below are based on scientific research, publications or traditional use. Because most herbs and supplements have not been thoroughly studied or monitored, safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients even within the same brand. Combination products often contain small amounts of each ingredient and may not be effective. Appropriate dosing should be discussed with a health care provider before starting therapy; always read the recommendations on a product's label. The dosing for unproven uses should be approached cautiously, because scientific information is limited in these areas.

One small study concluded that there is no difference between the absorption rates for the retarded versus nonretarded preparation and that daytime absorption was slightly better than nighttime absorption.

Adults (Aged 18 Or Older)

Children (Younger Than 18):  Horse chestnut seed extract should not be given to children because of a lack of research. Death has occurred when children have eaten raw horse chestnut seeds or tea made from horse chestnut leaves and twigs.


Although horse chestnut seed extract has been suggested for many conditions, the most promising use supported by science is the treatment of chronic venous insufficiency. Evidence does not support the use of horse chestnut seed extract for other health problems. Horse chestnut seed extract should be avoided by pregnant or breast-feeding women and by children, and it should be used cautiously by patients taking anticoagulants or drugs that affect blood sugar levels. Horse chestnut seed extract should be used only at recommended doses for up to 12 weeks. Consult your health care provider immediately if you experience side effects.

The information in this monograph was prepared by the professional staff at Natural Standard, based on thorough systematic review of scientific evidence. The material was reviewed by the Faculty of the Harvard Medical School with final editing approved by Natural Standard.


  1. Natural Standard: An organization that produces scientifically based reviews of complementary and alternative medicine (CAM) topics
  2. National Center for Complementary and Alternative Medicine (NCCAM): A division of the U.S. Department of Health & Human Services dedicated to research

Selected Scientific Studies: Horse Chestnut Seed Extract

Some of the more recent studies are listed below:

  1. Diehm C, Trampisch HJ, Lange S, et al. Comparison of leg compression stocking and oral horse-chestnut seed extract therapy in patients with chronic venous insufficiency. Lancet 1996;347(8997):292-294.
  2. Pittler MH, Ernst E. Horse chestnut seed extract for chronic venous insufficiency. Cochrane Database Syst Rev 2004;(2):CD003230.
  3. Pittler MH, Ernst E. Horse-chestnut seed extract for chronic venous insufficiency: a criteria-based systematic review. Arch Dermatol 1998;134(11):1356-1360.
  4. Popp W, Horak F, Jager S, et al. Horse chestnut (Aesculus hippocastanum) pollen: a frequent cause of allergic sensitization in urban children. Allergy 1992;Aug, 47(4 Pt 2):380-383.
  5. Siebert U, Brach M, Sroczynski G, Berla K. Efficacy, routine effectiveness, and safety of horse chestnut seed extract in the treatment of chronic venous insufficiency: a meta-analysis of randomized controlled trials and large observational studies. Int Angiol 2002;Dec, 21(4):305-315.
  6. Simini B. Horse-chestnut seed extract for chronic venous insufficiency. Lancet 1996;337(9009):1182-1183.
  7. Vayssairat M, Debure C, Maurel A, et al. Horse-chestnut seed extract for chronic venous insufficiency. Lancet 1996;347(9009):1182.

Last updated June 14, 2005