Herb Profile
Garlic Allium Sativum
Allium sativum
Garlic (Allium sativum) is most studied for cardiovascular support, including modest effects on blood pressure and lipids, alongside antimicrobial and immune modulating activity from organosulfur compounds like allicin and ajoene.
Last reviewed: •5 sources citedReport a correctionProfile-wide ·B Moderate
Use extra caution — GI upset; odor; potential bleeding risk at high intake Details
- Evidence
- Moderate Evidence
- Typical onset
- Varies by prep
- Safety rating
- Moderate caution
- Best for
- Cardiovascular, Antimicrobial, Immune, Inflammatory signaling
- Avoid / review if
- Bleeding Disorders, Pre Surgery, Anticoagulants
Safety
Safety & Cautions
GI upset; odor; potential bleeding risk at high intake
Elevated caution
Caution level: Elevated. One caution category applies — read it before use.
- Anticoagulant CautionBleeding or anticoagulant-adjacent caution language is present.
Detailed safety fields
Pregnancy, breastfeeding, and contraindications
- Bleeding Disorders
- Pre Surgery
- Anticoagulants
- Antiplatelets
Safety classifications
- Anticoagulant Caution: Bleeding or anticoagulant-adjacent caution language is present.
Full safety note
- GI upset; odor; potential bleeding risk at high intake
Safety labels
- Anticoagulant Caution
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.
Evidence
Evidence Summary
Evidence lens
Useful signal, but study design, dose, and population still matter.
ModerateModerate Evidence
Human clinical evidence: Present in source signals
Mechanistic / preclinical: Mechanism mapped — Metabolic Regulation · Vascular Function Support · Immune Signaling Modulation
Research maturity: Established research — Long Term Human Evidence May Be Limited.
Safety boundary: Safety note available — GI upset; odor; potential bleeding risk at high intake
This profile cites 5 human studies.
Study design details
Evidence Grade
Grade B: Moderate 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 11 recorded studies, 8 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 (11)7 human evidence sources · 1 human trial · ~210 participants across 1 human evidence source with reported N · Consistency not yet classifiable
Filter by study class
Showing 11 of 11 studies.
What the evidence actually shows
This table contains 11 structured sources, including 7 human evidence sources; 1 is a human trial. Across 1 human evidence source with a reported sample size, the approximate participant total is 210; overlapping publications may include some of the same people.
| 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. | — | — | — | — | — | Pooled RCT evidence supports favorable effects of garlic on selected dyslipidemia/lipid measures. | PubMed → |
Background | Meta-analysis Statistically combines results from multiple eligible studies; confidence still depends on the quality, consistency, and directness of those studies. | — | — | — | — | — | Garlic reduced fasting glucose, HbA1c, total cholesterol, and LDL and increased HDL in pooled analyses; triglycerides did not clearly improve. | PubMed → |
Background | Meta-analysis Statistically combines results from multiple eligible studies; confidence still depends on the quality, consistency, and directness of those studies. | — | — | — | — | — | Aged garlic modestly reduced systolic blood pressure and LDL; diastolic pressure and HDL were not clearly changed. | PubMed → |
Background | Meta-analysis Statistically combines results from multiple eligible studies; confidence still depends on the quality, consistency, and directness of those studies. | — | — | — | — | — | Pooled analyses reported improvements across several metabolic-syndrome components and inflammatory markers. | PubMed → |
Background | Meta-analysis Statistically combines results from multiple eligible studies; confidence still depends on the quality, consistency, and directness of those studies. | — | — | — | — | — | A large synthesis reported improvements in several lipid, glycemic, blood-pressure, and inflammatory markers while multiple endpoints, including several weight-related measures, were null. Endpoint-specificity and preparation identity are essential. | PubMed → |
Background | Meta-analysis Statistically combines results from multiple eligible studies; confidence still depends on the quality, consistency, and directness of those studies. | — | — | — | — | — | A 27-trial synthesis reported reductions in fasting glucose and HbA1c, while insulin and HOMA-IR were not significantly improved. The discordant biomarker pattern should remain visible. | PubMed → |
Show 5 more studies
PubMed · Pak J Pharm Sci · 2013 Background | Controlled trial Compares an intervention with a control group but may lack random assignment or other safeguards of a strong randomized trial. | n=210 | — | — | — | — | — | PubMed → |
Chemical Constituents and Pharmacological Activities of Garlic (Allium sativum L.): A Review El-Saber Batiha G et al. · Nutrients · 2020 Background | Narrative review Summarizes selected literature without the full prespecified search and selection methods of a systematic review. | — | — | — | — | — | — | PubMed → |
Allicin: chemistry and biological properties Borlinghaus J et al. · Molecules · 2014 Background | Narrative review Summarizes selected literature without the full prespecified search and selection methods of a systematic review. | — | — | — | — | — | — | PubMed → |
Fugh-Berman A et al. · Lancet · 2000 Background | Narrative review Summarizes selected literature without the full prespecified search and selection methods of a systematic review. | — | — | — | — | — | — | PubMed → |
Prevalence and pattern of congenital heart disease in Uttarakhand, India PubMed · Indian J Pediatr · 2013 Background | Other / unclear The study design is not yet classified clearly enough to infer its place in the evidence hierarchy. | — | — | — | — | — | — | PubMed → |
Dosing & Timing
- Dose guidance
- Aged garlic extract (~1.2 mg S allyl cysteine/day) or dried powder 600 1200 mg/day; composition varies by preparation
How Garlic Allium Sativum works
Simplified mechanism pathway based on preclinical and pharmacological evidence. Does not confirm clinical efficacy.
Mechanism Pathway — How Garlic Allium Sativum Works
CompoundTarget / ReceptorMechanismEffect / Outcome
Mechanisms & biological pathways (preclinical)
- Metabolic Regulation
- Vascular Function Support
- Immune Signaling Modulation
- Lipid Metabolism Support
- Endothelial Function Support
Active Compounds
Key constituents studied in Garlic Allium Sativum, 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
Garlic product picks
Affiliate recommendations for Garlic Allium Sativum. Review safety, dose, and product quality before buying.
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Product form & quality guidelines
When sourcing Garlic Allium Sativum, 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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