What does it mean when a product can "lock in" moisture?

Products that lock in moisture actually create a barrier between your hair and the surrounding environment. So the natural moisture in your hair—what helps it stay shiny and healthy—is kept in. And the moisture from outside—which can cause hair to frizz—is kept out. Look for products with silicone to help develop a barrier for your hair. From Pantene, you can choose products from the Daily Moisture Renewal collection. They’re great for all hair types and work especially well for creating noticeable improvement in damaged hair, which is most prone to frizz. Here’s how it works: silicone has positively charged ions and damaged hair is negatively charged, so these opposites attract. That means the silicone in our hair products is naturally drawn to the areas of your hair that need protection the most. When this protection is delivered—when the barrier is created—you get a balance of interior and exterior moisture needed for your hair to really look its best.