Research synthesisModerate evidenceSmall effect3 studies · 3 beneficial · 0 neutral · 0 harmful
Across 3 studies, all reported beneficial effects on reduced systolic blood pressure, with effect sizes ranging from small to moderate. The evidence is supported by two large meta-analyses (including one with 82 RCTs) showing small but statistically significant reductions (e.g., WMD = -3.25 mmHg). Most studies used doses of 200–4600 mg/day of Nigella sativa (black cumin), and the median study duration was 32 days, suggesting effects may be observed within 4–8 weeks.
- Effective dose range: 200–4600 mg/day
- Studied populations: patients with metabolic diseases, postmenopausal women with hypertension
Caveats: Evidence base is small (only 3 studies) — conclusions should be considered preliminary. Available evidence is overwhelmingly positive — clinical literature in this area is subject to publication bias (null-result studies are less likely to be published or indexed). The small effect size (around 3–4 mmHg reduction) may have modest clinical significance for blood pressure management.
Generated Jun 4, 2026