OBAGI Professional-C®, 30 ml, Skin Serums for Women, The OBAGI Professional-C® face serum is a product full of active ingredients, meaning it provides absolutely luxurious care for your skin. Characteristics: helps to smooth out wrinkles and fine lines firms the facial contours evens skin tone helps remove signs of skin ageing How to use: Use every morning and/or evening. Dab an appropriate amount of the serum gently into clean skin with your fingertips.