Often, people with oily, acne-prone skin neglect their moisturizers. The truth is even acne skin needs moisture. When the skin is denied moisture, the sebaceous glands take over and become more active and productive. It is the excess oil production that contributes to more acne. Also, the dry flakey skin from lack of moisture can block the follicles and incubate more bacteria that is trapped under the surface.
The use of a light moisturizer with a sunscreen is the best protection for acne skin. It provides a light veil of moisture and protects from the potential of post inflammatory hyperpigmentation which is a problem for acne skin as the blemishes heal. Additional moisture benefits, without the emollients contained in most moisturizers, can be found in aqueous product like toners and serums. Most of these will have humectant qualities (drawing moisture from the air) with the addition of antioxidants for healthier immune response.
For a list of recommended, light-weight moisturizers for your face, click here.