Horse chestnut seed extract has been shown to have some effect when used orally for symptomatic treatment of chronic venous insufficiency, such as varicose veins. It may also be useful for relieving pain, tiredness, tension, and swelling in the legs. It contains a number of anti-inflammatory substances, including escin, which reduces edema and lowers fluid exudation by decreasing vascular permeability.
References
Ref: Jones RH, Carek PJ: Management of varicose veins. Am Fam Physician 2008;78(11):1289-1294. 2)
Pittler MH, Ernst E: Horse chestnut seed extract for chronic venous insufficiency. Cochrane Database Syst Rev 2006;(1):CD003230.