Efficacy of Nigella Sativa (Nisatol®) in Women With Borderline Blood Pressure Values or a Non-Dipper Blood Pressure Phenotype

Hypertension represents one of the main risk factors for cardiovascular diseases, which remain the leading cause of mortality worldwide. In women, cardiovascular risk is often underestimated, resulting in lower adherence to preventive screening and frequent presentation at more advanced stages of cardiovascular disease. Many women present borderline blood pressure values or altered circadian blood pressure patterns, such as the non-dipper phenotype. These conditions may be associated with increased cardiovascular risk and may significantly affect quality of life, particularly in women experiencing climacteric symptoms. Nigella sativa (black cumin seed) has attracted increasing interest as a nutraceutical strategy for improving cardiovascular and metabolic health. Preliminary evidence suggests that supplementation with Nigella sativa may have beneficial effects on blood pressure, lipid profile, and heart rate. This randomized controlled trial will evaluate the efficacy of Nigella sativa (Nisatol®) supplementation compared with placebo in women with borderline blood pressure values and/or a non-dipper blood pressure phenotype. Participants will be randomly assigned to either the intervention group receiving Nisatol® or a control group receiving placebo using formulations that are visually indistinguishable. The initial treatment phase will last 12 weeks. After this phase, treatment will be discontinued and participants will undergo a washout period. Following the washout period, participants will begin a dietary intervention based on a standardized Mediterranean diet combined with the alternate treatment according to the study design. Participants will be evaluated at predefined time points (baseline, 4 weeks, 12 weeks, and final evaluation) to monitor blood pressure, resting heart rate, adherence to treatment, and potential adverse events. Additional assessments will include lipid profile, fasting blood glucose, body composition parameters, gut microbiota analysis, urinary metabolite analysis, and quality-of-life evaluation using validated questionnaires. The results of this study are expected to provide additional evidence regarding the potential role of Nigella sativa supplementation as a nutraceutical strategy for improving cardiovascular parameters and metabolic health in women with borderline blood pressure values.