We propose to perform a 24-week randomized, double-blind a placebo-controlled trial among 207 non-equol producing postmenopausal women with prehypertension to examine the effectiveness of equol (10mg and 20mg/d) on 24h ambulatory blood pressure, vascular function and other cardiovascular risks (lipid profile, glycemic control and inflammatory biomarkers) and explore the optimal dosage of equol.

Inclusion criteria

1. Hong Kong Chinese women aged 45-65 y with 2~8 years menopausal;
2. Mean SBP above 130 mmHg or DBP above 80 mmHg or both based on an average of 6 BP readings on two different occasions measured by sphygmomanometer.
3. Equol non-producer is defined as 24-hour urinary log10 S-equol:daidzein ratio less than -1.75 after daidzein challenge (60mg daidzein daily for 7 consecutive days).

Exclusion criteria

1. Subjects on anti-hypertensive medication or with average SBP≥160 or DBP≥100 or both;
2. Use of medications known to affect BP within past 6 months;
3. Medical history or presence of certain chronic diseases that could affect BP or limit the individual's ability to participate in the study;
4. Present or history of certain cancers;
5. Regular smoker or alcohol consumption more than 30 g/day;
6. Known soy allergy.

Inclusion Criteria:

1. Hong Kong Chinese women aged 45-65 y with 2~8 years menopausal;
2. mean SBP above 130 mmHg or DBP above 80 mmHg or both based on an average of 6 BP readings on two different occasions measured by sphygmomanometer.
3. Equol non-producer is defined as 24-hour urinary log10 S-equol:daidzein ratio less than -1.75 after daidzein challenge (60mg daidzein daily for 7 consecutive days).
4. Written informed consent will be obtained from all the participants prior to enrolment.

Exclusion Criteria:

1. Subjects on anti-hypertensive medication or with average SBP≥160 or DBP≥100 or both;
2. use of medications known to affect BP within past 6 months (hormone therapy, hypoglycemic or weight reduction agents);
3. medical history or presence of certain chronic diseases (stroke, cardiac infarction, severe liver and renal disease etc.) that could affect BP or limit the individual's ability to participate in the study;
4. present or history of breast cancer, endometrial cancer, ovarian cancer, thyroid disorder, abnormal uterine bleeding after menopause;
5. regular smoker or alcohol consumption more than 30 g/day;
6. known soy allergy.