What Are the Efficacy, Effects, and Contraindications of Cassia Seed (Cassiae Semen)?

Cassia seeds are a heat-clearing herb whose primary functions are clearing liver heat to improve vision and moistening the intestines to relieve constipation. They are commonly used to treat symptoms such as red, swollen, and painful eyes; blurred vision; headache; and dizziness—conditions arising from excessive liver heat or hyperactive liver fire. Modern pharmacological studies indicate that cassia seeds can lower plasma total cholesterol and triglyceride levels and reduce blood pressure. They are typically administered as a decoction or infusion in water. These herbs are bitter, salty, and cold in nature; therefore, they are contraindicated in individuals with spleen-stomach deficiency, qi deficiency, or loose stools.