That said, the cons of hyaluronic acid aren't a question of whether it is good or evil. It's a matter of how best to use it so that it helps your skin, rather than hurts it. The ingredient needs to be used in conjunction with other moisturizers; hyaluronic acid alone will not provide the necessary hydration skin needs. "It's really meant as a temporary hydrator, when applied to damp skin," Dr. Shamban says. "If your skin is already dry, you could actually be doing more harm than good."