Incorporating a serum into your skincare routine can make all the difference in the way your skin looks and feels. WHAT IS THE DIFFERENCE BETWEEN ULTRA FACIAL CREAM AND FACIAL FUEL MOISTURIZER? IS KIEHL’S ULTRA FACIAL CREAM GOOD FOR ACNE-PRONE SKIN? Hyaluronic acid is a sugar-based chemical found in our skin that keeps it hydrated, taut, and plump. Lactic acid is a great starting point (unless you are vegan). Why are these called "active ingredients"? The changing seasons are harsh on the…