If you thought that hyaluronic acid topped the class when it came to hydration, think again. Polyglutamic acid is four steps ahead of it – quite literally, because this humectant can hold four times the moisture that hyaluronic acid does. This supercharged ingredient is relatively new on the market, but we promise you that it’ll quickly go to the top spot in your skincare routine, especially if your skin is dry or dehydrated. Pro tip: Pair this active with hyaluronic acid or vitamin C for the ultimate hydration cocktail.