Galactose-alpha-1,3-galactose (often abbreviated as alpha-gal) is a carbohydrate found in the tissues of non-primate mammals, such as cows, pigs, and sheep. It is a type of sugar that can trigger an immune response in some humans, leading to allergic reactions. This sugar is not typically present in humans or other primates, which makes it unique. The presence of alpha-gal in certain foods, particularly red meat, can cause a condition known as alpha-gal syndrome. This syndrome is characterized by delayed allergic reactions, including hives and anaphylaxis, after consuming meat products. Understanding alpha-gal is important for managing dietary restrictions in affected individuals.