In this Phase III clinical trial, researchers evaluate the efficacy and safety of NW Roselle®, a powdered medicinal product developed by Natural Wellness. NW Roselle combines extracts from Hibiscus Sabdariffa (HS) flowers and Olea europaea (OE) leaves. The trial aims to gather evidence on the efficacy and safety of NW Roselle as a potential treatment option for Grade 1 essential hypertension.

Hypertension is a major risk factor for heart, brain, and kidney diseases, and is a leading cause of death and illness globally. Natural Wellness has developed NW Roselle®, a powdered medicinal product that combines extracts from Hibiscus Sabdariffa (HS) flowers and Olea europaea (OE) leaves.

In this Phase III clinical trial, researchers are evaluating the efficacy and safety of NW Roselle, in the treatment of Grade 1 essential hypertension. Eligible participants who meet the criteria will be enrolled and randomized in a 1:1 ratio. They will be assigned to receive either NW Roselle or an active control, Captopril 25 mg twice daily.

Before the treatment begins, participants will provide informed consent and undergo assessments to collect information about their medical history, hypertension status, lifestyle factors, and demographics. Throughout the trial, the participant's vital signs, physical exams, and laboratory tests will be conducted to monitor their health and response to the treatment. Adherence to the assigned treatment will be monitored, and any potential adverse events or side effects will be tracked.

Inclusion Criteria:

1. Diagnosed with grade 1 essential hypertension (Systolic Blood Pressure: 140-159 mmHg, and/or Diastolic Blood Pressure 90-99 mmHg) (Williams et al., 2018).
2. Not currently taking any medication for hypertension.
3. Able and willing to provide written informed consent.

Exclusion Criteria:

1. Pregnant or lactating women.
2. Patients with BMI > 45 Kg/m2 or BMI < 18 Kg/m2.
3. Patients with a known history of secondary hypertension (e.g., hyperaldosteronism, pheochromocytoma, renal artery stenosis, Cushing syndrome).
4. Renal impairment (Estimated Creatinine Clearance (Cr.Cl.) < 30 ml/min as measured by the Cockcroft-Gault formula).
5. Known Severe hepatic impairment, biliary cirrhosis, or cholestasis.
6. Patients with a history of arrhythmias, ischemic heart diseases, obstruction of the outflow tract of the left ventricle (e.g., hypertrophic obstructive cardiomyopathy, and high-grade aortic stenosis), congestive heart failure, valvular disease, myocardial infarction (MI), angina, myocardial revascularization, or cerebrovascular accident (CVA) within 6 months prior to study entry.
7. Participation in other clinical studies within 30 days before screening.
8. Known or suspected allergy or any contraindications to the trial products.