The original MET-Rx meal replacement product came in two canisters—one labeled MET-Rx "base" and the other MET-Rx "plus". The instructions were to take two scoops of the plus and one scoop of the base and mix them in milk or water. As the product grew more popular, it was released as one formula combining the "base" and "plus" while removing the micellar casein component. As a result, the original METAMYOSYN blend is no longer used in MET-Rx products, as the current ingredients does not contain micellar casein.