Plant MedicineGarlic

Garlic

Allium sativum

Family: Amaryllidaceae

Also known as: Common garlic, Stinking rose, Da suan, Rashona

At a glance

Best for: Cardiovascular health, Blood pressure, Immune support, Antimicrobial, Cholesterol
Parts used: Bulb, Cloves
Common forms: Culinary, Capsule, Aged garlic extract, Oil, Powder
Evidence level: Well-supported
Cautions: Blood-thinning effect—caution pre-surgery; Strong odour from supplements; May interact with blood thinners
Cardiovascular
Immune
Metabolic
Culinary
Capsule
Aged garlic extract
Oil
Powder
Central Asia
Iran

What it is

Garlic has been cultivated for over 5,000 years. When garlic cloves are crushed, the enzyme allinase converts alliin to allicin—the compound responsible for most of garlic's smell and medicinal effects. Other active compounds include S-allylcysteine (found in aged garlic), ajoene, and diallyl disulfide.

Traditional use

Used in ancient Egypt (workers building the pyramids received garlic rations for stamina), ancient Greece and Rome, Ayurveda, and Traditional Chinese Medicine. Hippocrates prescribed garlic for conditions including pulmonary disease. Used throughout history for infection during epidemics.

What modern research suggests (Well-supported)

Meta-analyses show significant blood pressure reduction (comparable to some antihypertensives in mild hypertension), LDL cholesterol reduction, and modest HDL improvement. Strong antimicrobial evidence including against antibiotic-resistant bacteria. Some evidence for reduced frequency of common colds.

How people use it

For cardiovascular benefit: aged garlic extract 600–1200mg/day (Kyolic) or enteric-coated allicin-standardised tablets. In food: crush 2–4 cloves of garlic daily and let sit 10 minutes before cooking. Raw garlic has highest allicin content. Roasted garlic is milder with different but still beneficial compounds.

Safety + interactions

Extremely safe as food. May cause digestive upset at high doses. Significant blood-thinning effect—stop garlic supplements at least 2 weeks before surgery. May reduce efficacy of HIV medications (saquinavir). Interaction with warfarin is possible at supplemental doses.

May interact with: Warfarin, Aspirin, HIV medications (saquinavir), Isoniazid

Quality notes

The key compound allicin is only produced when garlic is crushed or chopped and comes into contact with the enzyme allinase. Aged garlic extract (AGE, Kyolic) has different compounds but may be better tolerated. Enteric-coated tablets are preferred for allicin delivery. Garlic oil capsules have different compounds from allicin-producing forms. Cooking partially destroys allicin—crush garlic and let it sit 10 minutes before cooking to maximise allicin formation.

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Disclaimer: This content is educational and not medical advice. Always consult a qualified healthcare provider before using any herbs or supplements, especially if you are pregnant, nursing, taking medications, or have a medical condition.

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