Garlic Supplements for Blood Pressure: About 5 mm Hg in Trials, More in People With Hypertension
Pooled trials show garlic supplements lower blood pressure modestly, mostly in people with high readings. Several key papers come from one research group, some supported by an aged-extract maker, and a Cochrane review found too little evidence on heart attacks or strokes.
By Kymata Health Editorial Published Last checked
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Label: 1 caplet: 1,000 mg aged garlic extract powder (bulb).
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Key takeaways
From 10 sources- A 2016 meta-analysis of 20 trials (970 people) found garlic supplements lowered systolic pressure by 5.1 mm Hg and diastolic by 2.5 mm Hg vs placebo1.
- In trials of people with hypertension the drop was larger: 8.7 mm Hg systolic and 6.1 mm Hg diastolic1.
- A Cochrane review found too little evidence to say whether garlic reduces heart attacks, strokes or deaths in people with hypertension2.
- The meta-analysis was published in a supplement from a garlic symposium supported by Wakunaga and other companies, and one aged garlic extract trial was funded by Wakunaga14.
- Garlic supplements may raise bleeding risk with blood thinners, and garlic cut levels of the HIV drug saquinavir by about half in a small study56.
What this article covers
1 evidence profileThe evidence, graded
Pulled from the trial tables in our evidence profiles. Grades follow our evidence-grading policy.
Graded findings
1 row- AGrade ABlood pressureImproved Systolic pressure fell 5.1 mm Hg and diastolic 2.5 mm Hg versus placebo; in people with hypertension, 8.7 and 6.1 mm Hg.Garlic · Meta-analysis · n=970 · 2016 · PMID 26764326
The short answer
Garlic supplements lower blood pressure a little, and the effect is clearest in people whose pressure is already high1. NCCIH summarizes the evidence as limited and the effect as small5.
The trials measured blood pressure; a Cochrane review found too little evidence to say whether garlic changes heart attacks, strokes or deaths12.
What the pooled trials found
An updated 2016 meta-analysis included 20 placebo-controlled trials with 970 participants and found average falls of 5.1 mm Hg systolic and 2.5 mm Hg diastolic1. In trials of people with hypertension (140/90 mm Hg or higher), the falls were 8.7 mm Hg systolic (10 trials) and 6.1 mm Hg diastolic (6 trials)1.
Preparations varied across the trials, from garlic powder to aged garlic extract1. The same review notes that longer trials are needed to show any effect on cardiovascular events and deaths1.
A 2012 Cochrane review asked a stricter question, whether garlic lowers cardiovascular events and deaths in people with hypertension2. Only 2 small trials qualified, neither reported clinical outcomes, and the blood pressure estimates had wide confidence intervals2. Its authors reported no known conflicts of interest2.
One newer meta-analysis on aged garlic extract and blood pressure, published in 2024, was later retracted by its journal, so it is not counted here7.
The aged garlic extract trials
In a 12-week trial of 79 general-practice patients with uncontrolled systolic hypertension, aged garlic extract was added to existing blood pressure medicines3. The 2-capsule dose (480 mg) lowered systolic pressure by 11.8 mm Hg vs placebo, the 4-capsule dose showed a borderline drop of 7.4 mm Hg at 8 weeks (P = 0.07), and 1 capsule did not differ from placebo3.
In the AGE at Heart trial, 88 people with uncontrolled hypertension took 1.2 g aged garlic extract or placebo for 12 weeks4. Systolic pressure fell 5.0 mm Hg more than placebo (P = 0.016), and the authors reported larger drops in a subgroup they called responders4.
Who paid for the research
The 2016 meta-analysis appeared in a Journal of Nutrition supplement from the 2014 International Garlic Symposium, which was supported by companies including Wakunaga Pharmaceutical and Wakunaga of America, makers of Kyolic aged garlic extract18. Its author declared no conflicts but received travel sponsorship from Wakunaga of America to attend the symposium8.
The AGE at Heart trial was funded by a grant from Wakunaga of America, which also supplied the capsules49. The 2013 dose-response trial was funded by a Royal Adelaide Hospital grant, with capsules supplied by Vitaco Health; neither company was involved in the design or analysis, according to the papers910.
Who should be careful
NCCIH says oral garlic has been used safely in studies lasting as long as 7 years, with breath and body odor, stomach pain, gas and nausea as common side effects5. Take extra care in these situations:
- People on anticoagulants, aspirin or other drugs that affect bleeding, and anyone facing surgery: NCCIH says garlic supplements may increase bleeding risk and advises telling your providers5. One maker-funded 12-week trial reported no rise in bleeding risk in people on blood thinners, but it was small4.
- People on HIV medicines: in 10 healthy volunteers, garlic caplets cut saquinavir blood levels (AUC) by 51%, and levels were still only 60% to 70% of baseline after a 10-day washout6.
- People on diabetes medicines: NCCIH notes garlic supplements may lower blood sugar slightly in people with diabetes5.
- People on blood pressure medicines: the aged-extract trials added garlic to existing medicines, so readings may change and are worth tracking with the prescriber34.
- Pregnancy, breastfeeding and garlic allergy: NCCIH says amounts above those in food may not be safe in pregnancy or breastfeeding, and some people are allergic to garlic5.
Quick answers
Common questions
3 answersHow much garlic was used in the trials?
Does eating garlic do the same thing?
The trials tested supplements such as garlic powder and aged extract, so they do not show what cooking with garlic does1.
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Where to buy Garlic
Products from brands we partner with that contain Garlic. Check the amount per serving against the doses studied, and the label for other ingredients.
Garlic products from partner brands
1 product Paid links · we earn a commission- Quick pickHerbsProKyolic Aged Garlic Extract One Per Day Formula 250, 1,000 mg, 30 Caplets
1 caplet: 1,000 mg aged garlic extract powder (bulb)
$13.79one-timeChecked Oct 15, 2026
References
10 sources. Numbers in the text link here.
Sources cited in this article
10 sources- 1Garlic Lowers Blood Pressure in Hypertensive Individuals, Regulates Serum Cholesterol, and Stimulates Immunity: An Updated Meta-analysis and ReviewJ Nutr, 2016 · PMID 26764326
- 2Garlic for the prevention of cardiovascular morbidity and mortality in hypertensive patientsCochrane Database Syst Rev, 2012 · PMID 22895963
- 3Aged garlic extract reduces blood pressure in hypertensives: a dose-response trialEur J Clin Nutr, 2013 · PMID 23169470
- 4The effect of aged garlic extract on blood pressure and other cardiovascular risk factors in uncontrolled hypertensives: the AGE at Heart trialIntegr Blood Press Control, 2016 · PMID 26869811
- 5Garlic (Last Updated: February 2025)National Center for Complementary and Integrative Health (NCCIH), 2025
- 6The effect of garlic supplements on the pharmacokinetics of saquinavirClin Infect Dis, 2002 · PMID 11740713
- 7Retraction notice to "Effects of aged garlic extract on blood pressure in hypertensive patients: A systematic review and meta-analysis of randomized controlled trials"Prostaglandins Other Lipid Mediat, 2026 · PMID 42527229
- 8Garlic Lowers Blood Pressure in Hypertensive Individuals (full text with supplement sponsorship and author disclosures)J Nutr (Elsevier), 2016
- 9The AGE at Heart trial: full text with acknowledgments (PMC4734812)Integr Blood Press Control, 2016
- 10Aged garlic extract dose-response trial: full text with acknowledgments (PMC3561616)Eur J Clin Nutr, 2013
Garlic and other dietary supplements are not intended to diagnose, treat, cure or prevent any disease, and these statements have not been evaluated by the FDA. Talk to your clinician or pharmacist before starting a supplement, especially if you take prescription medicines. Product links on this page are paid partner links.