Aesculus hippocastanum, also known as Horse Chestnut, is a herb traditionally used to improve symptoms of chronic venous insufficiency (CVI) such as hemorrhoids and varicose veins. CVI leads to symptoms of itching, pain, discoloration and edema in the legs, creating both medical and aesthetic concerns. Modern research has confirmed that the active ingredient responsible for improving blood vessel integrity is known as escin. Escin has been found to increase nitric oxide production within the endothelial cells, thereby improving blood flow.
Clinical trials have found that horse chestnut extract can reduce pain and leg swelling associated with CVI and also significant reduction in symptoms, bleeding, and improvements in endoscopic evaluations in those with hemorrhoids. One trial showed that 82% of subjects had hemorrhoid improvements compared to only 32% in placebo, with most benefits acutely apparent within just six days of starting supplementation. Conversely, many studies for CVI find that maximum benefits occur within 1-3 months of supplementation. The evidence-based dose for Aesculus hippocastanum appears to be mostly dependent on escin content, which should reach a minimum 150mg per day, rather than the dried herb equivalent or total extract amount.