It regulates the pH of the skin, but if you have combination or dry skin, like I do, you should use an oil based cleanser before or a moisturizing mist after so you don't feel the tightness on your skin.
The only thing I don't like about this product is that it creates a foam when I applied it. although it vanishes later. Overall, except for that issue, it helps a lot with the breakouts.
I don't feel this product hydrates as much as other moisturizers but is super light and smells nice. My skin absorbs it really fast and is a good product to put under the makeup