What Is Horse Chesnut Extract?

Horse chestnut isn't a nut at all. Rather, it's a plant whose seeds, bark and leaves have been used to create medicine for hundreds of years. Horse chestnut extracts can be made from different parts of the plant, and are used to treat different ailments. Horse chestnut seed is used to treat diarrhea, fever and enlarged prostate. The bark of the plant is used to treat malaria and dysentery. Horse chestnut leaf is used to treat eczema, menstrual pain and swelling.

Active Ingredient

• Horse chestnut seed extract, the most common form of horse chestnut extract, contains a high percentage of aescin, the active ingredient. Sometimes known as escin, this chemical found in horse chestnut is known for its anti-inflammatory effects. It thins the blood and prevents fluid leakage out of veins and capillaries. Aescin also prevents water retention by acting as a diuretic, causing fluid loss through urine.

Effectiveness

• According to the U.S. National Library of Medicine (NLM), horse chestnut extract has been found effective in the treatment of varicose veins and other circulatory issues including poor circulation, varicose veins, swelling and water retention. The NLM lacks evidence to support horse chestnut extract's use in treating hemorrhoids, diarrhea, fever, cough, enlarged prostate, menstrual pain, swelling and other conditions.

Safety

• Horse chestnut extract is safe for most people to use on a short-term basis provided the toxic ingredient esculin has been removed. Raw horse chestnut seed, bar, flower and leaf can cause death due to the poisonous ingredient esculin. Pregnant and nursing women should avoid horse chestnut extract. People with diabetes may find that horse chestnut lowers their blood sugar. People with intestinal disorders should avoid horse chestnut because it can irritate the gastrointestinal tract. People with liver and kidney conditions should avoid horse chestnut extract because it can worsen those conditions.

Interactions

• While horse chestnut extract is not a prescription drug, it can interfere with both prescription drugs and other herbs and dietary supplements. Horse chestnut can interfere with prescription medicines such as lithium, diabetes drugs and anticoagulant drugs or drugs that slow blood clotting. It can interfere with herbs and supplements that lower blood sugar like chromium, garlic and ginseng. It can also interfere with herbs and supplements that slow blood clotting like angelica, clove, ginkgo and red clover.