Black Seed Oil
Evidence Fact Sheet
Nigella sativa
Black seed oil (Nigella sativa), rich in thymoquinone, is a dietary supplement studied for cardiometabolic and inflammatory markers via NF-kB inhibition and NRF2/AMPK signaling. Meta-analyses of RCTs report lipid, glycemic, CRP and body-weight changes; blood-pressure and waist-circumference effects are modest or null.
Also known as: Nigella sativa oil · Black cumin seed oil · Thymoquinone (TQ) · Kalonji oil
Overview
Black seed oil is pressed from the seeds of Nigella sativa (black cumin / kalonji); its principal bioactive constituent is thymoquinone. Mechanistic and preclinical work attributes its effects to NF-kB pathway inhibition, NRF2/ARE antioxidant-response activation, AMPK metabolic-signaling activation, and NLRP3 inflammasome modulation. Research trials and meta-analyses have most commonly used Nigella sativa seed oil 1-3 g/day or seed powder 1-2 g/day over roughly 8-12 weeks. In the United States it is sold as a dietary supplement under DSHEA (history of food use, no independent GRAS Notice; structure/function claims only); EFSA has no authorized or non-authorized health claims on file; and it is pending/case-by-case in China (Novel Food / SAMR route) and Brazil (ANVISA vegetable-oil framework). Most human evidence is in dysglycemic, dyslipidemic or overweight populations and is reported here as research findings, not as treatment of any disease.
Mechanism of Action
NF-kB pathway inhibition · NRF2/ARE antioxidant-response activation · AMPK metabolic-signaling activation · NLRP3 inflammasome modulation
Body systems: Cardiovascular · METABOLISM · Immune System · Respiratory & Mucosal Barrier · Liver & Detoxification
Evidence-Based Benefits
Each benefit below is anchored to a specific PubMed-indexed study. Effect sizes, sample sizes, and p-values are reported as published; no values are inferred. Honest negatives and null results are kept alongside the positive findings, and disease-research populations are described as such — Black Seed Oil is not characterized as a treatment for any disease.
Plasma Lipid Profile
Meta-analysis supported- -15.65 mg/dLtotal cholesterol · p=0.001
- -14.10 mg/dLLDL-C · p<0.001
In a meta-analysis of 17 randomized controlled trials, Nigella sativa supplementation was associated with significant reductions in total cholesterol, LDL-C and triglycerides, with a greater effect on total cholesterol and LDL-C reported for the seed oil specifically. HDL-C was not significantly changed.
Reported effect: Total cholesterol WMD -15.65 mg/dL (95% CI -24.67, -6.63, p=0.001); LDL-C WMD -14.10 mg/dL (95% CI -19.32, -8.88, p<0.001); triglycerides WMD -20.64 mg/dL (95% CI -30.29, -11.00, p<0.001)
“reduction in total cholesterol (weighed-mean-difference [WMD]: -15.65mg/dL, 95% CI: -24.67, -6.63, p=0.001), LDL-C (WMD: -14.10mg/dL, 95% CI: -19.32, -8.88, p<0.001), triglyceride levels (WMD: -20.64mg/dL, 95% CI: -30.29, -11.00, p<0.001) ... No significant effect on HDL-C concentrations (WMD: 0.28mg/dL, 95% CI: -1.96, 2.53, p=0.804) ... A greater effect of NS seed oil versus seed powder was observed on serum total cholesterol and LDL-C levels, and an increase in HDL-C levels was found only after NS seed powder supplementation.”
Source: PMID 26875640 · Sahebkar 2016 · Pharmacol Res
HDL Cholesterol (No Effect)
Null / no benefit Meta-analysis supported- 0.28 mg/dLHDL-C · p=0.804
An honest null within the same lipid meta-analysis: Nigella sativa supplementation showed no significant effect on HDL-C concentrations across the pooled trials; any HDL-C increase was seen only with seed powder, not the oil.
Reported effect: HDL-C WMD 0.28 mg/dL (95% CI -1.96, 2.53, p=0.804)
“No significant effect on HDL-C concentrations (WMD: 0.28mg/dL, 95% CI: -1.96, 2.53, p=0.804)”
Source: PMID 26875640 · Sahebkar 2016 · Pharmacol Res
Glycemic Indices
Meta-analysis supported- -21.43 mg/dLfasting glucose · p=0.005
- -0.44HbA1c · p=0.01
A 2025 meta-analysis of 16 randomized controlled trials found black seed supplementation significantly reduced fasting blood glucose and HbA1c. However, no significant effects were seen for 2-hour postprandial glucose, fasting insulin or HOMA, so the signal is limited to fasting glucose and HbA1c.
Reported effect: Fasting blood glucose MD -21.43 mg/dL (p=0.005); HbA1c MD -0.44 (p=0.01); no significant effect on 2-h postprandial glucose, fasting insulin or HOMA
“black seed supplementation significantly reduced fasting blood glucose (FBG) (MD: -21.43 mg/dL; p = 0.005), hemoglobin A1c (HbA1c) (MD: -0.44; p = 0.01) ... No significant effects were observed for 2-hour postprandial glucose (2-hpp), fasting insulin, homeostatic model assessment (HOMA)”
Source: PMID 40210172 · Karimi 2025 · Complement Ther Med
Blood Pressure (Modest)
Meta-analysis supported- -3.26 mmHgsystolic · vs control
- -2.80 mmHgdiastolic · vs control
A meta-analysis of 11 randomized controlled trials reported small reductions in systolic and diastolic blood pressure with Nigella sativa versus control. The magnitude is modest, and the authors noted powder formulations tended to outperform oil preparations.
Reported effect: Systolic BP -3.26 mmHg (95% CI -5.10, -1.42; I2=59%); diastolic BP -2.80 mmHg (95% CI -4.28, -1.32; I2=60%)
“The difference in reductions as compared with control/standard groups were -3.26 (-5.10, -1.42; I = 59%) mmHg in SBP and -2.80 (-4.28, -1.32; I = 60%) mmHg in DBP.”
Source: PMID 27512971 · Sahebkar 2016 · J Hypertens
Inflammatory Marker (CRP)
Meta-analysis supportedA meta-analysis of 5 randomized controlled trials found a significant reduction in serum C-reactive protein, a circulating inflammatory marker, with Nigella sativa supplementation. The evidence base is small (5 trials), so the finding is suggestive rather than definitive.
Effect size: not quantified on this page — see the linked study below for the reported figures.
Source: PMID 31331553 · Tavakoly 2019 · Complement Ther Med
Body Weight & BMI
Meta-analysis supported- -1.76 kgbody weight
- -0.85 kg/m2BMI
A meta-analysis of 13 trials (875 participants) reported significant reductions in body weight and BMI with Nigella sativa supplementation versus placebo. Heterogeneity was high, so individual results varied across trials.
Reported effect: Body weight WMD -1.76 kg (95% CI -3.34 to -0.17, I2=87.4%); BMI WMD -0.85 kg/m2 (95% CI -1.23, -0.46, I2=70.6%)
“NS supplementation significantly reduced BW (Weighted Mean Differences (WMD): -1.76 kg, 95% CI: -3.34 to -0.17, I2 = 87.4%) ... A significant reduction was seen in BMI (WMD: -0.85 kg/m2, 95% CI: -1.23, -0.46, I2 = 70.6%)”
Source: PMID 29857879 · Mousavi 2018 · Complement Ther Med
Waist Circumference (No Effect)
Null / no benefit Meta-analysis supported- -4.04 cmwaist circ · not significant
- 5 studiesWC subgroup
An honest negative from the body-composition meta-analysis: despite reductions in body weight and BMI, no significant reduction in waist circumference was found across the five studies that measured it.
Reported effect: Waist circumference WMD -4.04 cm (95% CI 11.37, 3.27, I2=97.8%), not significant
“However, no significant reduction was found in WC comparing NS supplementation to placebo (WMD: -4.04 cm, 95% CI: 11.37, 3.27, I2 = 97.8%) in five studies.”
Source: PMID 29857879 · Mousavi 2018 · Complement Ther Med
Dosage (research context · not a recommendation)
Research trials and meta-analyses most commonly used black seed (Nigella sativa) seed oil 1-3 g/day, or seed powder 1-2 g/day, over 8-12 weeks; thymoquinone is the principal active constituent. Educational reference describing the doses studied — not a dosing recommendation.
Regulatory Status · 4 Markets
- US · FDA
- Dietary supplement under DSHEA; Nigella sativa has a history of food use, no independent GRAS Notice (GRN); structure/function claims only
- EU · EFSA
- 0 authorized / 0 non-authorized health claims (no claim dossier submitted); food-use history but no EFSA claim evaluation — no health claim may be made cross-border in the EU
- CN · China
- Not a traditional Chinese food ingredient; requires Novel Food or health-food (SAMR) raw-material application/assessment and has no confirmed domestic approval to date.
- BR · ANVISA
- Vegetable-oil category subject to case-by-case ANVISA assessment (RDC 243/2018 framework); no standalone authorized functional (alegacao funcional) claim
Safety
Generally well tolerated at studied doses; mild GI discomfort most common. Thymoquinone may potentiate antidiabetic and anticoagulant/antiplatelet drugs — consult a clinician if on these. High doses not advisable (animal liver/kidney toxicity at extremes). Inadequate pregnancy/lactation data. Educational, not medical advice.
Related
Goals: heart-health · inflammation-relief
Lifestyles: senior-60-plus
References
PubMed-indexed citations anchoring the benefit findings above. Effect sizes are reported as published.
- PMID 26875640 · Sahebkar 2016 · Pharmacol Res — Plasma Lipid Profile
- PMID 40210172 · Karimi 2025 · Complement Ther Med — Glycemic Indices
- PMID 27512971 · Sahebkar 2016 · J Hypertens — Blood Pressure (Modest)
- PMID 31331553 · Tavakoly 2019 · Complement Ther Med — Inflammatory Marker (CRP)
- PMID 29857879 · Mousavi 2018 · Complement Ther Med — Body Weight & BMI
Frequently Asked Questions
1. What is black seed oil and what is its main active compound?
Black seed oil is pressed from the seeds of Nigella sativa (black cumin / kalonji), a plant with a long history of food use. Its principal bioactive constituent is thymoquinone. Mechanistic and preclinical research links its effects to NF-kB pathway inhibition, NRF2/ARE antioxidant-response activation, AMPK signaling and NLRP3 inflammasome modulation.
2. What doses were used in the research?
Across trials and meta-analyses, Nigella sativa was most commonly given as seed oil at 1-3 g/day or seed powder at 1-2 g/day, typically over about 8-12 weeks. This is an educational description of the doses studied, not a dosing recommendation.
3. What are the strongest evidence areas, and where is the evidence weak or null?
The most consistent meta-analytic signals are for plasma lipids (total cholesterol and LDL-C reductions, PMID 26875640) and fasting glucose / HbA1c (PMID 40210172), with smaller pooled effects for serum CRP (PMID 31331553) and body weight / BMI (PMID 29857879). Honest negatives matter too: HDL-C was not significantly changed (PMID 26875640), waist circumference was not significantly reduced (PMID 29857879), and the blood-pressure effect was modest (PMID 27512971).
4. Are there safety considerations?
At the doses studied black seed oil is generally well tolerated, with mild GI discomfort the most common complaint. Thymoquinone may potentiate antidiabetic and anticoagulant/antiplatelet medications, so anyone on those should consult a clinician. Very high doses are not advisable, and pregnancy/lactation data are inadequate. This is educational information, not medical advice.
Last evidence review: 2026-06-13