:This article is about ingredients in general. There is also an American soul and R&B group called The Main Ingredient. An ingredient is a substance that forms part of a mixture (in a general sense). For example, in cooking, recipes specify which ingredients are used to prepare a specific dish. Many commercial products contain a secret ingredient that's purported to make them better than competing products. In the pharmaceutical industry, an active ingredient is that part of a formulation that y… (More on Ingredients)