Carrageenan is a natural food additive derived from red seaweed, widely used as a thickener, stabilizer, and emulsifier in various products. It's commonly found in dairy products like ice cream, yogurt, and plant-based milk, as well as in processed meats and beverages. Carrageenan helps improve texture and shelf life, but its use has raised some concerns about potential digestive health effects, though it's generally considered safe by regulatory agencies like the FDA when consumed in moderate amounts.