According to the experts, the hero ingredient actually needs to be applied to damp skin in order to work. In fact, applying it to a dry face can have the opposite effect of what is intended, and actually leave skin more dehydrated. "Hyaluronic acid is a moisture magnet," says Allies of Skin founder Nicolas Travis. "But if your skin is dry, it pulls any residual moisture from the deeper layers of skin to hydrate the surface. In that case, you need to apply it to moist skin — which is why you should mist first and then apply a hyaluronic acid treatment afterwards. Once hyaluronic acid comes into contact with water, it knows what it's doing and your skin will end up supremely hydrated and plumped."