REDEFINE Intensive Renewing Serum is formulated with our proprietary Retinal-MD Technology to help deliver a potent amount of Retinal while reducing the potential for irritation. The Retinal-MD molecule is unique in that Calcium microspheres encapsulate the Retinal, creating a time-release delivery system to lower the potential for irritation. However, due to the high amount of Retinal, some people might experience signs of mild dryness, skin tightness and visible redness, which is a normal function of the skin. If you experience any of these signs, we recommend reducing the frequency of use to every other night. If your experience is beyond mild and tolerable or if irritation is persistent, we recommend discontinuation.