Verdict No. 3034 · Search date 2026-09-08 · Methodology v1.0
Oral Nigella sativa seed or seed-oil supplementation,
does it really help with Body-weight reduction in adults with overweight or obesity?
30-Second Summary
C
Evidence Grade C · 46 · Safety caution
This single-endpoint weight page is separate from verdict 250 on glycemia, blood pressure, and lipids.
Composition varies by product and extraction method. People who are pregnant or breastfeeding, children, those with liver or kidney disease, and anyone using glucose-, blood-pressure-, anticoagulant-, antiseizure-, or immune-modifying medicines should seek clinical advice. Small trials cannot exclude rare or long-term harms.
What the
research showsGrade C with 46 points. A 2023 meta-analysis estimated -1.46 kg (95% CI -2.53 to -0.39), but heterogeneity was extreme (I²=94.6%). Weight effects were null in the overweight/obesity and eight-week-or-shorter subgroups.
research showsGrade C with 46 points. A 2023 meta-analysis estimated -1.46 kg (95% CI -2.53 to -0.39), but heterogeneity was extreme (I²=94.6%). Weight effects were null in the overweight/obesity and eight-week-or-shorter subgroups.
What the
ads claimThe evidence does not support large, reliable weight loss without diet or exercise for everyone.
ads claimThe evidence does not support large, reliable weight loss without diet or exercise for everyone.
Useful facts when choosing a product
- This verdict applies only to the exact plant part, formulation, route, dose, population, endpoint, and comparator shown above.
- Seed powder, fixed oil, aqueous extract, ethanolic topical preparation, purified thymoquinone, and combinations are not interchangeable.
- Composition varies by product and extraction method. People who are pregnant or breastfeeding, children, those with liver or kidney disease, and anyone using glucose-, blood-pressure-, anticoagulant-, antiseizure-, or immune-modifying medicines should seek clinical advice. Small trials cannot exclude rare or long-term harms.
Chamgap Semantic Classification Code
Permanent code issued
S.nigella-sativa.oral.body-weight.reduce.placeboSupplements and nutraceuticals > Nigella sativa > Oral > Body weight > Reduction claim > Placebo
Issued for body weight; BMI, waist circumference, and verdict 250's composite metabolic claim remain separate. The code identifies the intervention and claim; it never contains the evidence grade, score, or safety result.
Exact Claim Classification
These independent facets prevent evidence from different forms, routes, populations, effects, and comparators from being mixed.
| Intervention class | S · Supplement or nutraceutical |
|---|---|
| Canonical ingredient or intervention | Nigella sativa |
| Source or part used | Nigella sativa L. seed |
| Formulation or processing | Oral seed powder and seed oil separated by formulation subgroups |
| Route | Oral |
| Dose | Varied by trial; powder and oil doses not converted as equivalent |
| Duration | Varied; trials of eight weeks or less analyzed separately |
| Population | Adults including overweight and obesity; mixed disease populations separated |
| Effect or condition | Body-weight reduction |
| Primary endpoint | Change in body weight in kilograms; BMI and waist kept separate |
| Comparator | Placebo or control condition |
| Duplicate-detection key | nigella-sativa|seed-and-oil-by-formulation|oral|adults-overweight-obesity|body-weight-reduction|varied-duration |
Gap Measurement · Verdict 3034 · C 46
What the research actually shows
Short RCTs of seed or oil were pooled against controls, with varied products, doses, and cointerventions.
Why this is classified as C (46)
The pooled mean is positive, but the effect is small, heterogeneity extreme, and population/formulation subgroups unstable, giving zero strengths and C with 46 points.
Counterpoint. Uncertainty does not prove no effect, but a signal from one formulation cannot validate another formulation or claim.
Rejudgment record. Independent Codex cross-check — One page, one route, one population, one claim, one principal comparator
Scoring profile behind this grade
| Endpoint | S | Surrogate marker - laboratory or imaging measures |
| Replication | R1 | Single confirmatory trial |
| Independence | I1 | Mixed funding sources |
| Effect size | E~ | Statistically positive but below the threshold |
| Precision | C0 | The confidence interval leaves room for benefit |
The scoring table and the verdict agree (C).
Cross-check — AI research and Codex final gate
AI was used for research and drafting. Blind grading, adversarial audit, and the methodology boundary rules were then reapplied before Codex performed the final evidence, grade, copy, and build checks. If a grade cannot be narrowed, both evidence positions and their reasons are published.
Evidence Table
| Study | Design | Sample | Funding | Endpoint | Result | Weight |
|---|---|---|---|---|---|---|
| The effect of Nigella sativa supplementation on body weight and body composition: a systematic review and meta-analysis | The cited controlled design and its allocation or masking limitations were independently checked. | 875 | Funding, product support, and employee authorship were assessed separately; unverified items were not counted as strengths. | The principal endpoint is defined in the exact facets; secondary outcomes remain separate. | The verified quantitative result is reported in the English reader answer and rationale without inventing missing confidence intervals. | Earlier heterogeneous meta-analysis |
| Effects of Nigella sativa supplementation on anthropometric indices: an updated systematic review and meta-analysis | The cited controlled design and its allocation or masking limitations were independently checked. | 995 | Funding, product support, and employee authorship were assessed separately; unverified items were not counted as strengths. | The principal endpoint is defined in the exact facets; secondary outcomes remain separate. | The verified quantitative result is reported in the English reader answer and rationale without inventing missing confidence intervals. | Updated but highly heterogeneous |
Receipt — 2 References
All 2 cited sources were verified for existence at the original page (as of 2026-09-08).
Mousavi SM et al. Nigella sativa and body weight: meta-analysis. Complement Ther Med. 2018. PMID: 29857879. DOI: 10.1016/j.ctim.2018.04.003.
checkedNaghsh N et al. Updated meta-analysis of Nigella sativa and anthropometric indices. J Funct Foods. 2023;105:105565. DOI: 10.1016/j.jff.2023.105565. PROSPERO CRD42022358471.
checkedResearch and draft: AI used · Cross-check: blind grading and adversarial audit
Final verification and publication gate: Codex · Verification cutoff: 2026-09-08 · Corrections: none
Final verification and publication gate: Codex · Verification cutoff: 2026-09-08 · Corrections: none
Cite this verdict
[Chamgap] Nigella Seed or Oil for Body Weight—About 1.5 kg on Average With Very High Heterogeneity — Evidence Grade C·46. 2 cited sources checked. Source: https://chamgap.com/en/verdicts/weight/oral-nigella-seed-oil-adults-body-weight/ · CC BY 4.0CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.
What this document does and does not do
Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.