Aescin, the extract from the dried seeds of the horse-chestnut plant, strengthens blood vessel walls, helping to prevent veins from softening and bulging, says Joseph Pizzorno, Jr., Doctor of Naturopathy and founding president of Bastyr University of Naturopathic Medicine in Seattle. “Horse-chestnut seed extract also reduces inflammation associated with varicose veins and stimulates regeneration of damaged veins,” he notes.