Studies have shown that drinking Hibiscus tea may lower blood pressure in people with type 2 diabetes, prehypertension, or mild hypertension. The effects of drinking hibiscus tea are comparable to blood-pressure medication.
Hibiscus tea has a tart, cranberry-like flavor, and sugar is often added to sweeten the beverage. The tea contains vitamin C and minerals and is used traditionally as a mild medicine.
Source: Wikipedia