Herb Profile
Nigella Sativa
Nigella sativa
Nigella sativa (Black Seed) is a traditional seed extract containing thymoquinone, studied for antioxidant and immune support.
Last reviewed: •3 sources citedReport a correctionProfile-wide ·A Strong
Use extra caution — May reduce glucose, lipids, and blood pressure; monitor with antidiabetics, antihypertensives, anticoagulants, and antiplatelets. Details
- Evidence
- Strong Evidence
- Typical onset
- Varies by prep
- Safety rating
- Moderate caution
- Best for
- Metabolic, Inflammatory signaling
- Avoid / review if
- Pregnancy At Supplemental/High Doses, Hypoglycemia Prone Patients Without Monitoring, Known Allergy.
Safety
Safety & Cautions
May reduce glucose, lipids, and blood pressure; monitor with antidiabetics, antihypertensives, anticoagulants, and antiplatelets. GI upset or allergic rash can occur.
Elevated caution
Caution level: Elevated. One caution category applies — read it before use.
Detailed safety fields
Pregnancy, breastfeeding, and contraindications
- Pregnancy At Supplemental/High Doses
- Hypoglycemia Prone Patients Without Monitoring
- Known Allergy.
- Antidiabetics
- Antihypertensives
- Anticoagulants/Antiplatelets
- Additive Metabolic Effects.
Full safety note
- May reduce glucose, lipids, and blood pressure; monitor with antidiabetics, antihypertensives, anticoagulants, and antiplatelets. GI upset or allergic rash can occur.
Evidence-based safety
Caution when combined
Severity and certainty are shown separately. A high-priority caution can still be theoretical: these pairings are screened from shared contraindication mechanisms and are not automatically documented clinical interactions. Provenance identifies the source fields that produced each flag; it does not upgrade the certainty of the pairwise claim.
High-Priority Caution
147 flagged pairingsBleeding / anticoagulant risk
High-Priority Caution
147 flagged pairingsBleeding / anticoagulant risk
Representative pairings are shown below. Large mechanism groups are intentionally summarized to keep profiles focused and crawl-efficient.
Bleeding / anticoagulant riskCertainty: Theoretical
Data provenance recorded for 147 of 147 pairings in this mechanism group.
- aescin — Theoretical interaction certainty
- Aged Garlic Extract — Theoretical interaction certainty
- ajoene — Theoretical interaction certainty
- Ajwain — Theoretical interaction certainty
- Allicin — Theoretical interaction certainty
- Garlic — Theoretical interaction certainty
- American Ginseng Extract — Theoretical interaction certainty
- Andrographis — Theoretical interaction certainty
- Angelica Archangelica — Theoretical interaction certainty
- Angelica Dahurica — Theoretical interaction certainty
- Angelica Pubescens — Theoretical interaction certainty
- Angelica Root — Theoretical interaction certainty
+135 more pairings share this mechanism. Use the Safety Checker to review a specific combination.
Moderate Caution
191 flagged pairingsBlood-sugar lowering · Blood-pressure effects
Moderate Caution
191 flagged pairingsBlood-sugar lowering · Blood-pressure effects
Representative pairings are shown below. Large mechanism groups are intentionally summarized to keep profiles focused and crawl-efficient.
Blood-sugar loweringCertainty: Theoretical
Data provenance recorded for 110 of 110 pairings in this mechanism group.
- Acarbose — Theoretical interaction certainty
- ajoene — Theoretical interaction certainty
- Allicin — Theoretical interaction certainty
- Aloe Vera — Theoretical interaction certainty
- Alpha-Lipoic Acid — Theoretical interaction certainty
- American Ginseng Extract — Theoretical interaction certainty
- Andrographis — Theoretical interaction certainty
- Anemarrhena Asphodeloides — Theoretical interaction certainty
- Tarragon — Theoretical interaction certainty
- Ashoka — Theoretical interaction certainty
- Astragalus — Theoretical interaction certainty
- Astragalus Membranaceus — Theoretical interaction certainty
+98 more pairings share this mechanism. Use the Safety Checker to review a specific combination.
Blood-pressure effectsCertainty: Theoretical
Data provenance recorded for 81 of 81 pairings in this mechanism group.
- Agmatine sulfate — Theoretical interaction certainty
- ajoene — Theoretical interaction certainty
- Allicin — Theoretical interaction certainty
- American Ginseng Extract — Theoretical interaction certainty
- Andrographis — Theoretical interaction certainty
- Angelica Dahurica — Theoretical interaction certainty
- Astaxanthin — Theoretical interaction certainty
- Astragalus Membranaceus — Theoretical interaction certainty
- Beetroot extract — Theoretical interaction certainty
- Berberis — Theoretical interaction certainty
- Bicarbonate — Theoretical interaction certainty
- Black Seed — Theoretical interaction certainty
+69 more pairings share this mechanism. Use the Safety Checker to review a specific combination.
Evidence
Evidence Summary
Evidence lens
Most useful for practical interpretation when safety context also fits.
StrongStrong Evidence
Human clinical evidence: Present in source signals
Mechanistic / preclinical: Mechanism mapped — Inflammatory Signaling Modulation · Metabolic Regulation · AMPK Signaling
Research maturity: Established research — Long Term Human Evidence May Be Limited.
Safety boundary: Safety note available — May reduce glucose, lipids, and blood pressure; monitor with antidiabetics, antihypertensives, anticoagulants, and antiplatelets.
This profile cites 3 human studies.
Study design details
Evidence Grade
Grade A: Strong Evidence
Evaluation of methodological rigor, population reach, and evidence alignment.
- Design Match
- Meta-analysis
- Risk of Bias
- Low
- Consistency
- Consistent
Strongest recorded design is a meta-analysis, drawn from 8 recorded studies, 5 in people. No disagreement is recorded across them.
How evidence grades work
Each grade reflects the strength and consistency of published human evidence — not marketing claims. Grades are based on study count, design quality, effect size, consistency, and recency.
- Strong
- Multiple RCTs, consistent direction, adequate effect size
- Moderate
- Some RCTs or consistent observational data in humans
- Preliminary / Mixed
- Animal or in-vitro only, or conflicting human data
- Traditional / Theoretical
- Traditional use only; no controlled human trials
Clinical Study Summaries (8)5 human evidence sources · 0 human trials · Participant totals not consistently reported · Consistency not yet classifiable
Filter by study class
Showing 8 of 8 studies.
What the evidence actually shows
This table contains 8 structured sources, including 5 human evidence sources; 0 are human trials.
| Study | Design | N | Dose | Duration | Population | Outcome | Result & magnitude | Source |
|---|---|---|---|---|---|---|---|---|
Background | Meta-analysis Statistically combines results from multiple eligible studies; confidence still depends on the quality, consistency, and directness of those studies. | — | — | — | — | — | A 2024 meta-analysis of three randomized trials (146 participants) found no significant effect on ICAM or VCAM endothelial/inflammatory markers, with severe heterogeneity. This is useful null evidence against overly broad cardiovascular-mechanism claims. | PubMed → |
Background | Meta-analysis Statistically combines results from multiple eligible studies; confidence still depends on the quality, consistency, and directness of those studies. | — | — | — | — | — | A 2024 systematic review/meta-analysis of 30 randomized trials reported reductions in fasting glucose and HbA1c, but heterogeneity was high. This supports a glycemic signal with moderate caution about pooled-study variability. | PubMed → |
Background | Meta-analysis Statistically combines results from multiple eligible studies; confidence still depends on the quality, consistency, and directness of those studies. | — | — | — | — | — | A 2025 GRADE-assessed synthesis of 82 randomized trials involving 5,026 participants reported pooled improvements across several glycemic and blood-pressure biomarkers with Nigella sativa. | PubMed → |
Background | Meta-analysis Statistically combines results from multiple eligible studies; confidence still depends on the quality, consistency, and directness of those studies. | — | — | — | — | — | Human trial synthesis reports modest blood-pressure effects in selected populations. Preparation identity and baseline hypertensive status should remain explicit, and biomarker changes should not become cardiovascular-outcome claims. | PubMed → |
Background | Meta-analysis Statistically combines results from multiple eligible studies; confidence still depends on the quality, consistency, and directness of those studies. | — | — | — | — | — | Randomized-trial synthesis reports changes in selected glycemic and cardiometabolic markers, but seed, oil, and extract preparations differ and biomarker changes do not establish diabetes treatment. | PubMed → |
A review on therapeutic potential of Nigella sativa: A miracle herb Ahmad A et al. · Asian Pac J Trop Biomed · 2013 Background | Narrative review Summarizes selected literature without the full prespecified search and selection methods of a systematic review. | — | — | — | — | — | — | PubMed → |
Show 2 more studies
Hannan MA et al. · Nutrients · 2021 Background | Narrative review Summarizes selected literature without the full prespecified search and selection methods of a systematic review. | — | — | — | — | — | — | PubMed → |
Alberts A et al. · Int J Mol Sci · 2024 Background | Narrative review Summarizes selected literature without the full prespecified search and selection methods of a systematic review. | — | — | — | — | — | — | PubMed → |
Dosing & Timing
- No standardized dose
- Preparation specific; use standardized product label for Preparation varies by tradition and product form and require source backed dosage review before therapeutic claims.
How Nigella Sativa works
Simplified mechanism pathway based on preclinical and pharmacological evidence. Does not confirm clinical efficacy.
Mechanism Pathway — How Nigella Sativa Works
CompoundTarget / ReceptorMechanismEffect / Outcome
Mechanisms & biological pathways (preclinical)
- Inflammatory Signaling Modulation
- Metabolic Regulation
- AMPK Signaling
- NF KB Modulation
- Nrf2 Activation
- Glucose Metabolism Support
Active Compounds
Key constituents studied in Nigella Sativa, with full pharmacology and safety profiles.
Compare related active botanicals
Explore botanicals with similar chemistry, effects, or safety considerations in the Botanical Activity Atlas.
Compare & Sourcing
Compare side-by-side tradeoffs or verify active marker guidelines.
Sourcing options
Black Seed (Nigella sativa) product picks
Recommendation status
Product recommendations are not shown for this profile because the current site safety and monetization policy does not permit them.
Product form & quality guidelines
When sourcing Nigella Sativa, verify the label for:
- Standardized extract: Confirm active content percentages on the supplement facts panel (e.g. standardized to specific marker compounds) rather than simple raw herb weights.
- Third-party testing: Look for independent purity labels (USP, NSF, ConsumerLab, or Eurofins) to ensure the product is free from heavy metals, solvents, and contaminants.
- Form bioavailability: Ensure the form matches evidence-supported configurations (e.g. standardized active extracts like bacosides, withanolides, or curcuminoids) for optimal onset and digestion tolerance.
Safety first · Harm reduction
This information is educational and not medical advice. Start low, avoid risky combinations, and consult a licensed clinician before making health decisions—especially if you use medications, have diagnosed conditions, or are pregnant/breastfeeding.
Learn how we evaluate confidence, safety, and intensity on the methodology page.
Founder & Head Researcher · Oak Ridge, TN · Last reviewed August 2026
Editorial Review
Checked against primary sources, cited evidence, and contraindication language before publication. Evidence claims, safety language, and affiliate modules are reviewed independently. Not personal medical advice.
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