Overview

What is garlic?

What are garlic’s main benefits?

What are garlic’s main drawbacks?

How does garlic work?

Dosage Information

Formulation

Garlic has been primarily studied in the forms of garlic powder, raw garlic, garlic oil, aged garlic extract, aged black garlic, fermented garlic, and garlic tablets.

Range of dosages studied

Dosages of garlic used in studies have ranged from 8 mg of garlic oil preparation to 40 grams (40,000 mg) of fermented garlic preparation daily and for 5 days to 48 weeks.

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Examine Database: Garlic

Health Condition/Goal	Health Outcome	Evidence
High Cholesterol	15 outcomes	58 Studies
General Cardiovascular Health	21 outcomes	11 Studies
High Blood Pressure	9 outcomes	9 Studies
Metabolic Health	14 outcomes	4 Studies
Coronary Artery Disease	15 outcomes	1 Study
Immune Health	16 outcomes	3 Studies
Common Cold	9 outcomes	2 Studies
Dyslipidemia	5 outcomes	77 Studies
H. Pylori Infection	1 outcome	2 Studies
Stomach Cancer	3 outcomes	3 Studies
Atherosclerosis	1 outcome	1 Study
Benign Prostatic Hyperplasia	2 outcomes	1 Study
Flu	9 outcomes	1 Study
Osteoporosis	3 outcomes	1 Study
Prostate Cancer	2 outcomes	1 Study
Type 2 Diabetes	6 outcomes	17 Studies
Acute Respiratory Infection	1 outcome	1 Study
Basal Cell Carcinoma	1 outcome	1 Study
Cardiovascular Disease	12 outcomes	1 Study
Lead Poisoning	1 outcome	1 Study
Metabolic Syndrome	14 outcomes	3 Studies
Peripheral Arterial Disease	1 outcome	1 Study
Peripheral Arterial Occlusive Disease	1 outcome	1 Study
General Athletic Performance	3 outcomes	1 Study

High Cholesterol

15 outcomes

General Cardiovascular Health

21 outcomes

High Blood Pressure

9 outcomes

Metabolic Health

14 outcomes

Coronary Artery Disease

15 outcomes

16 outcomes

9 outcomes

5 outcomes

1 outcome

3 outcomes

1 outcome

Benign Prostatic Hyperplasia

2 outcomes

9 outcomes

3 outcomes

2 outcomes

6 outcomes

Acute Respiratory Infection

1 outcome

Basal Cell Carcinoma

1 outcome

Cardiovascular Disease

12 outcomes

Lead Poisoning

1 outcome

Metabolic Syndrome

14 outcomes

Peripheral Arterial Disease

1 outcome

Peripheral Arterial Occlusive Disease

1 outcome

General Athletic Performance

3 outcomes

Safety Information
New

Research FeedRead all studies

Frequently Asked Questions

Does garlic affect cardiovascular health?

Does garlic affect cold and flu?

What are other names for Garlic?

Update History

14 days ago

FAQ update
major

Research written by

Wyatt Brown

Edited by

Conni Covington

Reviewed by

Katie Jantz

February 25, 2026

Examine Database update
minor

February 25, 2026

Examine Database update
minor

February 25, 2026

Examine Database update
correction

February 25, 2026

Examine Database update
minor

December 18, 2025

Safety information update
minor

Research written by

Giulia Guerrini

Edited by

Conni Covington

Reviewed by

Katie Jantz

September 4, 2025

Safety Information added
major

Research written by

Giulia Guerrini

Edited by

Conni Covington

Reviewed by

Katie Jantz

Research Breakdown

The Examine Research Breakdown has been archived. The Examine team will be incorporating the information in this section throughout the site after a thorough review to ensure it is up to date.

References

Examine Database References

Health Condition/Goal	Health Outcome	Evidence
High Cholesterol	15 outcomes	58 Studies
General Cardiovascular Health	21 outcomes	11 Studies
High Blood Pressure	9 outcomes	9 Studies
Metabolic Health	14 outcomes	4 Studies
Coronary Artery Disease	15 outcomes	1 Study
Immune Health	16 outcomes	3 Studies
Common Cold	9 outcomes	2 Studies
Dyslipidemia	5 outcomes	77 Studies
H. Pylori Infection	1 outcome	2 Studies
Stomach Cancer	3 outcomes	3 Studies
Atherosclerosis	1 outcome	1 Study
Benign Prostatic Hyperplasia	2 outcomes	1 Study
Flu	9 outcomes	1 Study
Osteoporosis	3 outcomes	1 Study
Prostate Cancer	2 outcomes	1 Study
Type 2 Diabetes	6 outcomes	17 Studies
Acute Respiratory Infection	1 outcome	1 Study
Basal Cell Carcinoma	1 outcome	1 Study
Cardiovascular Disease	12 outcomes	1 Study
Lead Poisoning	1 outcome	1 Study
Metabolic Syndrome	14 outcomes	3 Studies
Peripheral Arterial Disease	1 outcome	1 Study
Peripheral Arterial Occlusive Disease	1 outcome	1 Study
General Athletic Performance	3 outcomes	1 Study

Safety Information

New

Visit Safety Checker Page

Summary
Side Effects
Interactions
Pregnancy & Lactation
Precautions
WADA Status

Safety Summary

Generally well tolerated. Garlic breath/body odor and gastrointestinal symptoms are most commonly reported with oral use. Topical application may cause skin irritation.
Several possible drug interactions, including with blood-thinning agents, saquinavir, and medications metabolized by CYP2E1.
Garlic is safe during pregnancy and lactation when consumed in amounts normally found in the diet, but the safety of supplementation has not been established. Caution is warranted.

Side Effects

Garlic appears to be a generally safe and well tolerated supplement.

Rarely, allergic reactions have been reported with oral and topical garlic. Symptoms can include hives, allergic dermatitis, angioedema (swelling of the mouth/lips), and anaphylaxis.^[12]

Effect	Details
^[12]	Route: Oral Notes: More pronounced when eating raw garlic or taking supplements containing garlic powder.
Full safety information is available to Examine Pro members. Try free for 14 days.

Interactions

Agent	Effect	Level of Evidence	Level of Severity
	Garlic may increase the risk of bleeding when combined with warfarin.^[26]	Level of Evidence: Possible	Level of Severity: Severe
Full safety information is available to Examine Pro members. Try free for 14 days.

Pregnancy and Lactation

Condition	Safety Information
Pregnancy Caution	Dietary garlic is generally considered safe during pregnancy when consumed in moderation. However, higher quantities may lead to mild gastrointestinal side effects, such as heartburn or nausea,^[12] which are already common in pregnancy and could cause discomfort. Regarding garlic supplements, limited research exists on their safety during pregnancy. Therefore, large quantities should be avoided until more studies are conducted. In one randomized controlled trial, women in their third trimester of pregnancy took 800 mg of garlic per day for the prevention of preeclampsia, and no significant side effects were observed, except for garlic odor.

Pregnancy

Caution

Dietary garlic is generally considered safe during pregnancy when consumed in moderation. However, higher quantities may lead to mild gastrointestinal side effects, such as heartburn or nausea,^[12] which are already common in pregnancy and could cause discomfort.

Regarding garlic supplements, limited research exists on their safety during pregnancy. Therefore, large quantities should be avoided until more studies are conducted. In one randomized controlled trial, women in their third trimester of pregnancy took 800 mg of garlic per day for the prevention of preeclampsia, and no significant side effects were observed, except for garlic odor.

Precautions

Precautions for specific demographics, populations, and/or conditions

Population/Condition	Details
	Garlic has been associated with bleeding due to its antiplatelet activity.^[12]^[22] Therefore, it is advisable to discontinue garlic supplementation 7–10 days before undergoing surgery.
Full safety information is available to Examine Pro members. Try free for 14 days.

World Anti-Doping Agency
Not Prohibited

According to the 2026 WADA List of Prohibited Substances, garlic is not prohibited.

Route: Oral
Notes: More pronounced when eating raw garlic or taking supplements containing garlic powder.

Full safety information is available to Examine Pro members. Try free for 14 days.

Garlic may increase the risk of bleeding when combined with warfarin.^[26]

Level of Evidence:

Possible

Level of Severity:

Severe

Full safety information is available to Examine Pro members. Try free for 14 days.

Condition	Safety Information
Pregnancy Caution	Dietary garlic is generally considered safe during pregnancy when consumed in moderation. However, higher quantities may lead to mild gastrointestinal side effects, such as heartburn or nausea,^[12] which are already common in pregnancy and could cause discomfort. Regarding garlic supplements, limited research exists on their safety during pregnancy. Therefore, large quantities should be avoided until more studies are conducted. In one randomized controlled trial, women in their third trimester of pregnancy took 800 mg of garlic per day for the prevention of preeclampsia, and no significant side effects were observed, except for garlic odor.

Pregnancy

Caution

Population/Condition	Details
	Garlic has been associated with bleeding due to its antiplatelet activity.^[12]^[22] Therefore, it is advisable to discontinue garlic supplementation 7–10 days before undergoing surgery.
Full safety information is available to Examine Pro members. Try free for 14 days.

Garlic has been associated with bleeding due to its antiplatelet activity.^[12]^[22] Therefore, it is advisable to discontinue garlic supplementation 7–10 days before undergoing surgery.

Full safety information is available to Examine Pro members. Try free for 14 days.

Garlic

Overview

What is garlic?

What are garlic’s main benefits?

What are garlic’s main drawbacks?

How does garlic work?

Dosage InformationMedical disclaimer

Formulation

Range of dosages studied

Supplements Demystified: Get Our Unbiased, Evidence-Based Guide

Examine Database: Garlic

Safety InformationNew

Research FeedRead all studies

Frequently Asked Questions

Does garlic affect cardiovascular health?

Does garlic affect cold and flu?

What are other names for Garlic?

Update History

FAQ updatemajor

Examine Database updateminor

Examine Database updateminor

Examine Database updatecorrection

Examine Database updateminor

Safety information updateminor

Safety Information addedmajor

Research Breakdown

References

Examine Database References

Examine Database: Garlic

Safety InformationNew

Table of Contents

Safety Summary

Side Effects

Interactions

Pregnancy and Lactation

Precautions

Precautions for specific demographics, populations, and/or conditions

World Anti-Doping Agency Not Prohibited

Table of Contents

Safety Summary

Side Effects

Interactions

Pregnancy and Lactation

Precautions

Precautions for specific demographics, populations, and/or conditions

World Anti-Doping Agency Not Prohibited

Dosage Information

Safety Information
New

FAQ update
major

Examine Database update
minor

Examine Database update
minor

Examine Database update
correction

Examine Database update
minor

Safety information update
minor

Safety Information added
major

Safety Information
New

World Anti-Doping Agency
Not Prohibited

World Anti-Doping Agency
Not Prohibited