Research synthesisHigh evidenceLarge effect4 studies · 4 beneficial · 0 neutral · 0 harmful
Across all 4 studies in the database, all 4 reported beneficial effects of black cumin (Nigella sativa) supplementation on reducing total cholesterol, with a predominant moderate-to-large effect size. The most comprehensive evidence comes from a 2025 meta-analysis of 82 RCTs (5,026 participants) and a 2024 meta-analysis (2,278 participants), both reporting statistically significant reductions in total cholesterol. The median study duration was 7 days (based on only 1 of 4 studies reporting duration), which is too short to infer long-term effects; however, the broader meta-analyses included trials lasting multiple weeks.
- Effective dose range: 200 to 4600 mg/day
- Studied populations: general adults, patients with type 2 diabetes, patients with metabolic syndrome
Caveats: Available evidence is overwhelmingly positive — clinical literature in this area is subject to publication bias (beneficial studies are more likely to be published and indexed). All 4 studies in the database are meta-analyses, which aggregate existing trials, so the overall quality is high; however, individual trials within these meta-analyses may vary in quality and duration. The reported median study duration of 7 days is based on only 1 study and is not representative of the typical trial lengths included in the meta-analyses.
Generated Jun 4, 2026