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Does garlic lower blood pressure and cholesterol?

Pooled trials show garlic supplements lower systolic blood pressure by about 4 mm Hg - more when readings start high - and trim LDL and total cholesterol.

Published October 2026

Short answer

Pooled trials show garlic lowers systolic blood pressure by about 4 mm Hg - more in people with high readings - and LDL and total cholesterol by a few mg/dL. Effects are modest and vary; garlic adds to, not replaces, treatment. Evidence grade B (Moderate). Meta-analyses of over 100 randomised trials for blood pressure; the effect is consistent in direction but small and measured on surrogate markers (blood pressure, cholesterol), and the cholesterol evidence is weaker, reflected in the topic's C grade.

Key takeaways

  • Across 108 randomised trials with 7,137 adults, garlic supplements lowered systolic blood pressure by about 3.7 mm Hg and diastolic by about 2.0 mm Hg on average [1].
  • In people with high blood pressure the drops are bigger - about 4.2/3.1 mm Hg in a 2025 review of 10 trials, and about 8.7/6.1 mm Hg in an earlier review's high-blood-pressure subgroup [2][3].
  • Pooled analyses find total cholesterol about 10 to 14 mg/dL lower and LDL about 6 to 8 mg/dL lower on garlic, but a careful 6-month trial of raw garlic, powder and aged extract found no cholesterol change at all [1][4][5].
  • Garlic forms are not interchangeable: aged garlic extract trials found smaller average blood pressure drops (about 2.5 mm Hg systolic) than pooled trials of all forms, and results vary widely between studies [6][7].
  • The common complaints are garlic breath, body odour and stomach upset, and garlic's possible effect on bleeding matters around surgery and blood thinners - though a 12-week warfarin trial found no extra bleeding [8][2][9].

The short version

Garlic - raw, powdered, or as an aged extract - lowers blood pressure a little, and the effect is biggest in people whose readings are already high [1][3]. Pooled across 108 randomised trials with 7,137 adults, systolic blood pressure was about 3.7 mm Hg lower and diastolic about 2.0 mm Hg lower on garlic than on placebo [1]. Total and LDL cholesterol also fall a few mg/dL in pooled results, but that part of the evidence is weaker: a careful 6-month trial of raw garlic, powder and aged extract found no cholesterol change [1][5].

What the studies show

The largest analysis pooled 108 randomised trials of garlic supplements in adults with a wide range of health conditions [1]. Compared with placebo, systolic blood pressure fell by about 3.7 mm Hg and diastolic by about 2.0 mm Hg, with larger drops in people whose baseline risk factors were worse [1]. An earlier meta-analysis of 20 trials with 970 people found systolic pressure 5.1 mm Hg lower overall; in people whose blood pressure started above 140/90, the fall was 8.7 mm Hg systolic and 6.1 mm Hg diastolic [3].

Reviews in people with diagnosed hypertension agree on the direction. A 2025 meta-analysis of 10 trials found drops of about 4.2/3.1 mm Hg, with bigger effects at higher starting readings and longer treatment [2]. A 2015 analysis of 17 trials found the systolic fall - about 4.4 mm Hg - only in people with high blood pressure, not in people with normal readings [10]. One 2015 review of 9 trials in hypertension found even larger falls (9.1 mm Hg systolic, 3.8 mm Hg diastolic) but with high heterogeneity: the trials disagreed, and the effect shrank when only the higher-quality trials were combined [7].

The form of garlic matters. A 2025 meta-analysis of 19 trials of aged garlic extract found a smaller systolic drop, about 2.5 mm Hg, and no clear effect on diastolic pressure or HDL cholesterol [6]. In a 12-week trial in people already taking blood pressure medication, an aged black garlic extract added a drop of about 1.8/1.5 mm Hg [11]. A 3-month trial of 1,600 mg a day of garlic powder in 90 people with metabolic syndrome found bigger drops, about 7.7/6.7 mm Hg, plus a small HDL rise [12].

For cholesterol, pooled results are positive but smaller and less consistent. The 108-trial analysis found total cholesterol about 10 mg/dL lower and LDL about 6 mg/dL lower, with HDL about 2 mg/dL higher [1]. A 2024 meta-analysis of 21 trials in people with raised blood fats found total cholesterol about 25 mg/dL lower and LDL about 17 mg/dL lower, with stronger effects in people over 50 [13]. Another 2024 review found total cholesterol 14 mg/dL lower and LDL 8 mg/dL lower, with no change in triglycerides [4]; a small triglyceride drop did appear in the 108-trial analysis [1].

Not every trial agrees. In a 6-month study, 192 adults with moderately high LDL cholesterol took raw garlic, garlic powder, aged garlic extract or placebo - about a clove a day, 6 days a week - and none of the forms changed LDL or other blood fats [5]. In adults who already had coronary artery disease, a review of six trials found total cholesterol about 16 mg/dL lower but no significant change in LDL [14]. An older review found cholesterol reductions at 1 and 3 months that had disappeared by 6 months [15]. In people with diabetes, a meta-analysis of 33 studies found total cholesterol about 17 mg/dL lower and LDL about 10 mg/dL lower [16].

The nuances

The people who benefit most are those with high readings to begin with: the systolic drop is larger in people with hypertension [3][2], smaller when blood pressure is already controlled with medication [11], and not significant in people with normal blood pressure [10]. The forms are not interchangeable: raw garlic, powder and aged extract differ, and the pooled results differ between them [6][5]. Some analyses carry high heterogeneity, effects shrank when only higher-quality trials were pooled, and one review of trials in metabolic syndrome warned of possible publication bias [7][17]. Trial doses ranged from about a clove of raw garlic a day [5] to 1,600 mg a day of garlic powder [12] and small amounts of S-allyl-cysteine from aged extract [11][18].

Garlic is generally well tolerated; adverse reactions were slightly but not significantly more frequent than placebo in a 2025 review [2]. Garlic breath and body odour are the best-documented complaints, and stomach discomfort and bad breath were the most common side effects in that review [8][2]. Because garlic may affect platelets and clotting, bleeding is a consideration for people on blood thinners or facing surgery: case reports describe heavy bleeding during surgery after high garlic intake, while a 12-week trial of aged garlic extract added to warfarin found no increase in bleeding, and a small study found a dietary amount of raw garlic (4.2 g) did not change platelet function [19][9][20]. Garlic can also reduce blood levels of the HIV medicine saquinavir [8]. The Garlic topic page has the full safety list and the doses used in trials.

What this means for you

A fall of roughly 4 mm Hg in systolic pressure is modest, and useful mainly for people whose readings are already high; the cholesterol changes are smaller still [1]. For comparison, a 28-day trial funded by the maker of the statin studied found a low-dose statin lowered LDL cholesterol by about 35%, while garlic and five other supplements did not beat placebo over that month [21]. So garlic supplements are a small extra, not a substitute for blood pressure or cholesterol treatment. If you take blood thinners - or have surgery planned - it is worth telling your doctor about any garlic supplements, because of the bleeding question [8].

Go deeper

  • Garlic — Garlic supplements lower blood pressure by a few points in trials - about 4 mm Hg systolic on average, and more in people who already have high blood pressure.

References

  1. Effects of Garlic Supplementation on Cardiovascular Risk Factors in Adults: A Comprehensive Updated Systematic Review and Meta-Analysis of Randomized Controlled Trials.. Nutr Rev, 2026.
  2. Meta-analysis on the safety and efficacy of long-term garlic consumption as an adjunctive treatment for hypertension.. Front Nutr, 2025.
  3. Garlic Lowers Blood Pressure in Hypertensive Individuals, Regulates Serum Cholesterol, and Stimulates Immunity: An Updated Meta-analysis and Review.. J Nutr, 2016.
  4. Effects of Garlic on Glucose Parameters and Lipid Profile: A Systematic Review and Meta-Analysis on Randomized Controlled Trials.. Nutrients, 2024.
  5. Effect of raw garlic vs commercial garlic supplements on plasma lipid concentrations in adults with moderate hypercholesterolemia: a randomized clinical trial.. Arch Intern Med, 2007.
  6. 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.. Phytother Res, 2025.
  7. A systematic review and metaanalysis on the effects of garlic preparations on blood pressure in individuals with hypertension.. Am J Hypertens, 2015.
  8. Garlic (Allium sativum L.): adverse effects and drug interactions in humans.. Mol Nutr Food Res, 2007.
  9. Aged garlic extract may be safe for patients on warfarin therapy.. J Nutr, 2006.
  10. Effect of garlic on blood pressure: a meta-analysis.. J Clin Hypertens (Greenwich), 2015.
  11. Antihypertensive Effects of an Optimized Aged Garlic Extract in Subjects with Grade I Hypertension and Antihypertensive Drug Therapy: A Randomized, Triple-Blind Controlled Trial.. Nutrients, 2023.
  12. Effects of garlic powder supplementation on metabolic syndrome components, insulin resistance, fatty liver index, and appetite in subjects with metabolic syndrome: A randomized clinical trial.. Phytother Res, 2021.
  13. Garlic consumption can reduce the risk of dyslipidemia: a meta-analysis of randomized controlled trials.. J Health Popul Nutr, 2024.
  14. Effects of garlic extract on lipid profile in patients with coronary artery disease: A systematic review and meta-analysis of randomised clinical trials.. Int J Clin Pract, 2021.
  15. Garlic shows promise for improving some cardiovascular risk factors.. Arch Intern Med, 2001.
  16. The effect of garlic on lipid profile and glucose parameters in diabetic patients: A systematic review and meta-analysis.. Prim Care Diabetes, 2019.
  17. Effects of garlic supplementation on components of metabolic syndrome: a systematic review, meta-analysis, and meta-regression of randomized controlled trials.. BMC Complement Med Ther, 2023.
  18. Effects of an Optimized Aged Garlic Extract on Cardiovascular Disease Risk Factors in Moderate Hypercholesterolemic Subjects: A Randomized, Crossover, Double-Blind, Sustainedand Controlled Study.. Nutrients, 2022.
  19. Garlic-Induced Surgical Bleeding: How Much Is Too Much?. A A Case Rep, 2016.
  20. Garlic at dietary doses does not impair platelet function.. Anesth Analg, 2007.
  21. Comparative Effects of Low-Dose Rosuvastatin, Placebo, and Dietary Supplements on Lipids and Inflammatory Biomarkers.. J Am Coll Cardiol, 2023.