Garlic (Allium sativum L. fam. Alliaceae) is one of the most researched and best-selling herbal products on the market. For centuries it was used as a traditional remedy for most health-related disorders. Also, it is widely used as a food ingredient--spice and aphrodisiac. Garlic's properties result from a combination of variety biologically active substances which all together are responsible for its curative effect. The compounds contained in garlic synergistically influence each other so that they can have different effects. The active ingredients of garlic include enzymes (e.g. alliinase), sulfur-containing compounds such as alliin and compounds produced enzymatically from alliin (e.g. allicin). There is a lot of variation among garlic products sold for medicinal purposes. The concentration of Allicin (main active ingredient) and the source of garlic's distinctive odor depend on processing method. Allicin is unstable, and changes into a different chemicals rather quickly. It's documented that products obtained even without allicin such as aged garlic extract (AGE), have a clear and significant biological effect in immune system improvement, treatment of cardiovascular diseases, cancer, liver and other areas. Some products have a coating (enteric coating) to protect them against attack by stomach acids. Clinically, garlic has been evaluated for a number of purposes, including treatment of hypertension, hypercholesterolemia, diabetes, rheumatoid arthritis, cold or the prevention of atherosclerosis and the development of tumors. Many available publications indicates possible antibacterial, anti-hypertensive and anti-thrombotic properties of garlic. Due to the chemical complexity of garlic and the use of different processing methods we obtain formulations with varying degrees of efficacy and safety.