Prehypertension and mild hypertension are associated with an increased risk of atherosclerosis and coronary artery disease, and often complicated with the metabolic disorder of glucose and lipid. The comprehensive prevention of hypertension is still an important and complex clinical issue. Peppermint is a popular flavoring agent, and peppermint tea help relax tension and could lower blood pressure. The effect of oral peppermint on blood pressure is not consistent, however, our previous animal study has shown that oral administration of menthol, the main component of peppermint, could reduce 24-hour mean arterial systolic and diastolic blood pressure in spontaneous hypertensive rats. Furthermore, menthol increases uncoupling protein(UCP)1 dependent thermogenesis and energy expenditure through transient receptor potential melastatin(TRPM)8 activation, and helps prevent obesity and metabolic disorders. In a prospective, double-blind, randomized, and parallel-group study, we will evaluate the effects of DANSHU capsule(menthol) on blood pressure and metabolic parameters in prehypertensive and mild hypertensive patients. This study will help develop future comprehensive prevention and treatment strategies for hypertension.

Inclusion Criteria:

• Blood pressure: 120mmHg≤SBP<160mmHg, and/or 80mmHg≤DBP<100mmHg

Exclusion Criteria:

• Diabetes
• Hypertension: SBP≥160mmHg, or DBP≥100mmHg
• known allergy to trial drugs
• Myocardial infarction or cerebrovascular accident in the year preceding the trial
• Clinical Congestive Heart Failure
• Secondary hypertension
• Pregnancy or lactating women
• Malignant tumor
• Gastroesophageal reflux or gastroduodenal ulcer
• History of hepatitis or cirrhosis
• History of kidney disease
• Body weight﹤35Kg