Botanical

Garlic Extract

Allium sativum

Evidence TierCWADA NOT PROHIBITED

tuneTypical Dose

960 mg daily of aged garlic extract for 12 weeks, with other studies using different standardized preparations

watchEffect Window

Blood-pressure and lipid effects generally take weeks, not days.

check_circleCompliance

WADA NOT PROHIBITED

Overview

Clinical Summary

Garlic extract can modestly lower blood pressure and improve some lipid markers, especially in higher-risk adults, but it is an adjunctive cardiometabolic supplement rather than a natural statin or antimicrobial cure-all.

Garlic has one of the more real but still modest cardiovascular evidence bases among common botanicals. The strongest human evidence supports small reductions in blood pressure and some lipid improvements, especially in adults with hypertension or worse baseline cardiometabolic risk. The evidence does not support treating garlic as a substitute for antihypertensives, statins, or antibiotics. Formulation matters, with many positive studies using aged garlic extract or other standardized preparations.

Garlic contains sulfur compounds such as allicin derivatives and S-allylcysteine that may affect vascular tone, endothelial function, and lipid metabolism. Those mechanisms are plausible, but the human evidence is still best framed around modest blood-pressure and lipid effects rather than broad antimicrobial or anti-atherosclerotic claims.

Outcomes

What This Is Expected To Influence

Primary Outcomes

  • Modest reduction in blood pressure
  • Modest improvement in some lipid markers

Secondary Outcomes

  • Greater benefit in adults with worse baseline cardiometabolic risk
  • Weak support for broad antimicrobial use claims

Safety

Contraindications and Interactions

Contraindications

  • Upcoming surgery
  • Active severe reflux or garlic intolerance

Side effects

  • Garlic odor or body odor
  • GI upset or reflux
  • Nausea

Interactions

  • Anticoagulant or antiplatelet drugs
  • Antihypertensive medications

Avoid if

  • You are using it in place of blood-pressure or lipid treatment
  • You are about to undergo surgery
  • You do not tolerate garlic or sulfur-rich botanicals

Evidence

Study-level References

ge-SRC-001Systematic review and meta-analysis
Sourceopen_in_new

Du Y, Zhang Q, Liu S, et al. Effects of Garlic Supplementation on Cardiovascular Risk Factors in Adults. A comprehensive updated systematic review and meta-analysis of randomized controlled trials. Nutrients. 2025;17(12):2051. doi:10.3390/nu17122051. PMID:40580481.

Population: Adults across randomized controlled trials of garlic supplementation for cardiovascular risk factors.

Dose protocol: Various garlic supplement protocols across randomized cardiometabolic trials

Key findings: Modest improvements in blood pressure and lipid markers, strongest in adults with worse baseline risk.

Notes: Best current overview for the supplement’s main use case.

Paper content

This updated 2025 meta-analysis is the best current high-level source for garlic's cardiometabolic use case. It supports modest improvements in blood pressure and lipids, particularly in adults who start with worse cardiovascular risk profiles. It does not support treating garlic as a substitute for statins, antihypertensives, or antimicrobial therapy.

ge-SRC-002Systematic review and meta-analysis
Sourceopen_in_new

Wang HP, Yang J, Qin LQ, et al. Garlic for hypertension. A systematic review and meta-analysis of randomized controlled trials. World J Gastroenterol. 2015;21(16):4935-4948. doi:10.3748/wjg.v21.i16.4935. PMID:25837272.

Population: Adults in randomized placebo-controlled trials of garlic for hypertension.

Dose protocol: Garlic-only formulations in hypertensive adults

Key findings: Reduced systolic and diastolic blood pressure versus placebo.

Notes: Main blood-pressure meta-analysis anchor.

Paper content

This meta-analysis remains a key blood-pressure source because it quantified the modest but real antihypertensive effect of garlic-only formulations. The benefit is clinically relevant enough to justify adjunctive use framing, but still far short of evidence for replacing standard antihypertensive therapy.

ge-SRC-004Randomized controlled trial.
Sourceopen_in_new

Gharagozloo Hesari N, Jahanian Sadatmahalleh S, Mohebbi P, Nasiri M, Khosravi A. Efficacy of garlic (Allium sativum) on metabolic syndrome components in women with polycystic ovary syndrome: randomized controlled trial. J Health Popul Nutr. 2025;44(1). doi:10.1186/s41043-025-01025-8. PMID:40770379.

Population: Women with PCOS and metabolic syndrome.

Dose protocol: 500 mg garlic tablets (2-3 mg allicin) twice daily for 8 weeks

Key findings: Significant improvements in fasting blood sugar (10.5%), triglycerides (17.8%), LDL cholesterol (14.2%), and CRP (24.7%) versus placebo.

Notes: Extends garlic's cardiometabolic evidence to younger women with PCOS and metabolic syndrome.

Paper content

This RCT tested 500 mg garlic tablets (containing 2-3 mg allicin) twice daily for 8 weeks in 97 women with PCOS and metabolic syndrome. The garlic group showed significant improvements across multiple metabolic markers compared to placebo, including a 10.5% reduction in fasting blood sugar, 17.8% reduction in triglycerides, 14.2% reduction in LDL cholesterol, and 24.7% reduction in C-reactive protein. Blood pressure and BMI also improved. The study extends garlic's cardiometabolic evidence base to a younger female population with hormonal metabolic dysfunction, supporting the broader pattern that garlic supplementation provides the most benefit in people with elevated baseline metabolic risk.

ge-SRC-003Randomized controlled trial
Sourceopen_in_new

Ried K, Frank OR, Stocks NP, et al. Aged garlic extract lowers blood pressure in patients with treated but uncontrolled hypertension. A randomised controlled trial. Maturitas. 2010;67(2):144-150. doi:10.1016/j.maturitas.2010.05.016. PMID:20594781.

Population: Adults with treated but uncontrolled hypertension.

Dose protocol: 960 mg aged garlic extract daily for 12 weeks

Key findings: Lowered systolic blood pressure in adults with treated but uncontrolled hypertension.

Notes: Practical RCT with a real-world hypertensive population.

Paper content

This aged-garlic trial is the best practical RCT for blood-pressure framing because it studied a real-world population with treated but uncontrolled hypertension. The systolic reduction was meaningful enough to support adjunctive use, but the sample was still small and the evidence remains formulation specific.

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