Background Information
Garlic consists of the bulb of alluim sativism, a member of the family Liliaceae. The bulbs contain an odorless, sulfur-containing amino acid derivative known as alliin. When bulbs are ground, the enzyme alliinase converts alliin to allicin, an antibacterial agent and precursor to the various active constituents.

Garlic supplements are marketed in a variety of forms: fresh, powders, oils, and tablets. Fresh garlic is the better product. Dried garlic contains neither allicin, the antibacterial principle, nor ajoene, the anti-clotting agent but it produces them in the small intestine following ingestion. Dried garlic preparations are most effective if tablets are enteric coated so they can pass through the stomach.

 Effects on Health
Garlic has been used historically to treat a variety of conditions including abscesses, coughs, poisonings, digestive and circulatory problems, and snakebites. More recently, garlic has been promoted as an anti-atherosclerotic and blood lipid lowering agent. The exact mechanism is not known; it is believed to be related to its ability to inhibit aggregation of blood platelets and to act as an HMG-CoA reductase inhibitor. Ajoene, a derivative of alliin, is the anti-clotting agent; it has similar properties to aspirin. Data also shows that garlic has benefits as an anti-hypertensive agent both in the systemic and pulmonary vasculature.

Moderate amounts of garlic do not pose any health risk for normal, healthy individuals. Large amounts of garlic can produce heartburn, flatulence, and gastrointestinal problems. Allergies have also been reported.

 Effects on Performance
No data on effects of garlic on performance.

 Recommendation
Cloves: one or two averaged size (4 grams) cloves of garlic daily for a 175 lb. person.
Powder: 900 mg/d yielding approximately 5000 mcg of allicin on ingestion.