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
Garlic Allium Sativum monograph visual
The Hippie Scientist illustration

At a glance

From this profile's structured data
Evidence
Grade B
Safety
GI upset; odor; potential bleeding risk at high intake
Profile context
cardiovascular, antimicrobial, immune
Next steps

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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.

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 mappedMetabolic Regulation · Vascular Function Support · Immune Signaling Modulation

Research maturity: Established researchLong Term Human Evidence May Be Limited.

Safety boundary: Safety note availableGI 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 10 recorded studies, 7 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 (9)5 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 9 of 9 studies.

What the evidence actually shows

This table contains 9 structured sources, including 5 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.

StudyDesignNDoseDurationPopulationOutcomeResult & magnitudeSource

Garlic consumption can reduce the risk of dyslipidemia: a meta-analysis of randomized controlled trials

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

Effects of Garlic on Glucose Parameters and Lipid Profile: A Systematic Review and Meta-Analysis on Randomized Controlled Trials

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

The Effect of Aged Garlic Supplementation on Blood Pressure and Lipid Profile: A Dose-Response Grade-Assessed Systematic Review and Meta-Analysis of Randomized Controlled Trials

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

Effect of garlic on the components of metabolic syndrome: A systematic review and meta-analysis of randomized controlled trials

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

Effects of Allium sativum (garlic) on systolic and diastolic blood pressure in patients with essential hypertension

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=210PubMed

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
Show 3 more studies

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

Herb-drug interactions

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

How Garlic Allium Sativum WorksGarlic Allium Sativum acts on biological target pathways via metabolic (regulation), leading to cardiovascular.Garlic Allium SativumBiological TargetBiological pathwayMetabolicRegulationCardiovascularObservable outcomeVascular FunctionSupport
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.

Guides that use Garlic Allium Sativum

Compare & Sourcing

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Sourcing options

Garlic 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 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.

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.

Editorial Standards →

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