Garlic is a plant in the onion family that’s grown for its distinctive taste and health benefits. It contains sulfur compounds, which are believed to bring some of the health benefits. Garlic is low in calories and rich in vitamin C, vitamin B6 and manganese. It also contains trace amounts of various other nutrients. Garlic supplements help prevent and reduce the severity of common illnesses like the flu and common cold. High doses of garlic appear to improve blood pressure for those with known high blood pressure (hypertension). In some instances, supplements may be as effective as regular medications. Garlic supplements seem to reduce total and LDL cholesterol, particularly in those who have high cholesterol.