Herbs & Supplements:
Horse Chestnut
Aesculus hippocastanum
Principal Proposed Uses
•
Vein Problems, Varicose Veins, Phlebitis, Hemorrhoids
Other Proposed Uses
•
Easy Bruising, Swelling from Sprains and Other Injuries
The horse chestnut tree is widely cultivated for its bright white, yellow, or red flower clusters. Closely related to the Ohio buckeye, this tree produces large seeds known as horse chestnuts. A superstition in many parts of Europe suggests that carrying these seeds in your pocket will ward off rheumatism. More serious medical uses date back to nineteenth-century France, where extracts were used to treat hemorrhoids.
What Is Horse Chestnut Used for Today?
Serious German research of this herb began in the 1960s and ultimately led to the approval of a horse chestnut extract for vein diseases of the legs. Horse chestnut is the third most common single herb product sold in Germany, after ginkgo and St. John's wort. In Japan, an injectable form of horse chestnut is widely used to reduce inflammation after surgery or injury; however, it is not available in the United States.
The active ingredients in horse chestnut appear to be a group of chemicals called saponins, of which escin is considered the most important. Like OPCs and bilberry, escin has the capacity to reduce swelling and inflammation, probably by slowing down the rate at which fluid leaks from irritated capillaries.1 It's not exactly clear how escin works, but theories include "sealing" leaking capillaries, improving the elastic strength of veins, preventing the release of enzymes (known as glycosaminoglycan hydrolases) that break down collagen and open holes in capillary walls, and blocking other physiological events that lead to vein damage.2,3
Horse chestnut is most often used as a treatment for venous insufficiency. This is a condition associated with varicose veins, when the blood pools in the veins of the leg and causes aching, swelling, and a sense of heaviness. While horse chestnut appears to reduce these symptoms, it is not believed to improve visible varicose veins very much.
Because hemorrhoids are actually a form of varicose veins, horse chestnut is often recommended for them as well.
Based on its known effects on veins, horse chestnut is also sometimes used along with conventional treatment in cases where the veins of the lower legs become seriously inflamed (phlebitis). However, this condition is potentially dangerous and requires a doctor's supervision.
Just like OPCs, extracts of horse chestnut are sometimes recommended to help reduce swelling after sprains, other athletic injuries, and surgery. Again, this use is based on the known effects of horse chestnut on blood vessels, and there is some evidence that it may be effective.4
Finally, one preliminary study suggests that a gel made from horse chestnut might be helpful for bruises.5
What Is the Scientific Evidence for Horse Chestnut?
More than 800 individuals have been involved in double-blind placebo-controlled studies of horse chestnut for treating venous insufficiency.6–14
One of the largest of these trials followed 212 people over a period of 40 days.15 It was what is called a crossover study because the participants initially received horse chestnut or placebo, and then were crossed over to the other treatment (without their knowledge) after 20 days. The results showed that horse chestnut produced significant improvement in leg edema, pain, and sensation of heaviness. However, the design of this study was not quite up to modern standards.
A better-designed double-blind study of 74 individuals also found benefit.16
Good results were also seen in a partially double-blind placebo-controlled study, which compared the effectiveness of horse chestnut to that of compression stockings, a standard treatment.17 This study followed 240 people over a course of 12 weeks. Compression stockings worked faster at reducing swelling, but by the end of the study the results were equivalent, and both treatments were better than placebo.
An extract of horse chestnut called escin may also help with bruising. One double-blind study of 70 people found that about 10 g of 2% escin gel, applied externally to bruises in a single dose 5 minutes after they were induced, reduced bruise tenderness.18
Dosage
The most common dosage of horse chestnut is 300 mg twice daily, standardized to contain 50 mg escin per dose, for a total daily dose of 100 mg escin. After good results have been achieved, the dosage can be reduced by about half for maintenance.
Horse chestnut preparations should certify that a toxic constituent called esculin has been removed (see Safety Issues). Also, a delayed-release formulation must be used to prevent gastrointestinal upset.
Safety Issues
Whole horse chestnut is classified as an unsafe herb by the FDA. Eating the nuts or drinking a tea made from the leaves can cause horse chestnut poisoning, the symptoms of which include nausea, vomiting, diarrhea, salivation, headache, breakdown of red blood cells, convulsions, and circulatory and respiratory failure possibly leading to death.19 However, manufacturers of the typical European standardized extract formulations remove the most toxic constituent (esculin) and standardize the quantity of escin. To prevent stomach irritation caused by another ingredient of horse chestnut, the extract is supplied in a controlled-release product, which reduces the incidence of irritation to below 1%, even at higher doses.20
Properly prepared horse chestnut products appear to be quite safe.21 After decades of wide usage in Germany, there have been no reports of serious harmful effects, and even mild reported reactions have been few in number.
In animal studies, horse chestnut and its principal ingredient escin have been found to be very safe, producing no measurable effects when taken at dosages seven times higher than normal. Dogs and rats have been treated for 34 weeks with this herb without harmful effects.22Studies in pregnant rats and rabbits found no injury to embryos at doses up to 10 times the human dose, and only questionable effects at 30 times the dose.
However, individuals with severe kidney problems should avoid horse chestnut.23,24,25 In addition, injectable forms of horse chestnut can be toxic to the liver.26
Horse chestnut should not be combined with anticoagulant or "blood-thinning" drugs, as it may amplify their effect.27,28 The safety of horse chestnut in young children and pregnant or nursing women has not been established. However, 13 pregnant women were given horse chestnut in a controlled study without noticeable harm.29
Interactions You Should Know About
If you are taking aspirin,Plavix (clopidogrel), Ticlid (ticlopidine), Trental (pentoxifylline), or anticoagulant drugs such as Coumadin (warfarin) or heparin, do not use horse chestnut except under medical supervision.
View References
Last reviewed March 2002 by Medical Review Board
Back to Top
