The crossword solution for the term CERTS INGREDIENT is RETSYN, which is a six-letter word. RETSYN is an artificial sweetener that was developed in the 1950s by the Calorie Control Council. It is composed of two components, aspartame and acesulfame potassium, and is used to sweeten food and beverages. It is considered to be a safe alternative to sugar and is used in many products, including diet sodas, candy, and chewing gum.