Side Effects and Cautions

• Homemade preparations of horse chestnut should not be used. Raw horse chestnut seeds, leaves, bark, and flowers contain esculin, which is poisonous.
• When properly processed, horse chestnut seed extract contains little or no esculin and is considered generally safe. However, the extract can cause some side effects, including itching, nausea, or gastrointestinal upset.
• Tell your health care providers about any herb or dietary supplement you are using, including horse chestnut. This helps to ensure safe and coordinated care.