Ready to feel more confident when reading your beauty products' ingredient labels? Enter, the Allure Ingredient Index. In this comprehensive guide, you'll find everything you need to know about the most in-demand (and under-the-radar) ingredients in your favorite skin-care products. When it comes to getting dewy, hydrated skin, few products deliver the way some of the best hyaluronic acid serums do. While the fact that "acid" makes up 50 percent of the name hyaluronic acid, don't be fooled into thinking the ingredient is not for everyone; in fact, the substance is naturally produced by our bodies and holds up to 1,000 times its weight in water. However, your skin's level of hyaluronic acid decreases with age, so if you're looking to maintain your moisture barrier and ramp up hydration levels, you may want to consider incorporating HA-laced products into your daily skin-care routine. "[Hyaluronic acid] is great at holding water and giving skin resilience and firmness," New York City-based board-certified dermatologist Doris Day, M.D., tells Allure. "This not only helps the skin look beautiful, but also helps it function at its best. We can inject hyaluronic acid into the deeper layers of the skin to help restore lost volume, but used in creams and serums it can also do wonders for rejuvenation and hydration." Even as we transition into warmer months, our skin will likely crave extra moisture to counteract sun exposure. Here, we present 23 of the best hyaluronic acid serums to give your skin some serious TLC year-round.