Garlic is a commonly used food and flavoring agent. When used as a food product, garlic is not likely to produce health benefits or side effects. When used as a medicinal product, garlic may produce both desired and unwanted effects on the body.

Garlic products sold as health supplements may vary widely in amount of allicin, the active ingredient in garlic. Allicin is unstable and can be reduced in garlic products that are aged to reduce odor. Odorless garlic may contain little to no allicin. The lower the amount of allicin, the less effective a garlic product might be.

Garlic has been used for blood vessel disease (atherosclerosis) and high blood pressure (hypertension).