Research synthesisLow evidenceSmall effect3 studies · 2 beneficial · 1 neutral · 0 harmful
Based on 3 meta-analyses, 2 reported beneficial small-to-moderate effects of black cumin (Nigella sativa) supplementation on reduced body weight, with one large meta-analysis of 82 RCTs (n=5,026) showing significant improvement and another meta-analysis of 31 trials (n=2,145) reporting a mean weight reduction of -1.59 kg. However, one meta-analysis in type 2 diabetes patients found no significant effect on body weight. The median study duration across reporting studies was only 7 days, which is insufficient to assess weight loss outcomes.
- Effective dose range: 200 to 4600 mg/day
- Studied populations: patients with metabolic diseases, general participants from 82 RCTs
Caveats: Evidence base is small (only 3 studies) — conclusions should be considered preliminary. One meta-analysis in T2DM patients found no significant effect, suggesting the benefit may not generalize to all populations. The median study duration of 7 days (from the single study reporting duration) is far too short to meaningfully assess weight loss — most weight loss interventions require 8-12 weeks to show effect, so these short-term findings may not reflect sustained weight reduction.
Generated May 16, 2026