Hyaluronic acid’s main feature is not its ability to moisturize the skin, but to maintain its moisture. This, in turn, helps dissipate the appearance of fine lines and promote collagen production. Those are important anti-aging benefits for your face as well as for your body. To buy: $9 (was $10); amazon.com. “My skin was horrible & nothing was working,” one reviewer shared. “I bought this on a whim and was amazed how well it worked.”