Alliin is primarily known for its role as a precursor to allicin, a compound responsible for the characteristic odor and many of the health benefits associated with garlic. When garlic is crushed or chopped, the enzyme alliinase converts alliin into allicin, which exhibits strong antimicrobial, antifungal, and antiviral properties. Due to this transformation, alliin contributes indirectly to the medicinal effects of garlic, including support for cardiovascular health by helping to lower blood pressure and reduce cholesterol levels. It is widely used in dietary supplements aimed at boosting immune function and promoting heart health. Alliin is also studied for its antioxidant effects, which help protect cells from oxidative stress and may reduce the risk of chronic diseases such as cancer. In food applications, it plays a role in flavor development, especially in processed garlic products where enzymatic activity is controlled to modulate taste. Because alliin itself is odorless, it is preferred in supplements over raw garlic to provide health benefits without the strong smell.