We present a physically-based approach for simulating makeup in face images. The key idea is to decompose the face image into intrinsic image layers - namely albedo, diffuse shading, and specular highlights - which are each differently affected by cosmetics, and then manipulate each layer according to corresponding models of reflectance. Accurate intrinsic image decompositions for faces are obtained with the help of human face priors, including statistics on skin reflectance and facial geometry. The intrinsic image layers are then transformed in appearance according to measured optical properties of cosmetics and proposed adaptations of physically-based reflectance models. With this approach, realistic results are generated in a manner that preserves the personal appearance features and lighting conditions of the target face while not requiring detailed geometric and reflectance measurements. We demonstrate this technique on various forms of cosmetics including foundation, blush, lipstick, and eye shadow. Results on both images and videos exhibit a close approximation to ground truth and compare favorably to existing techniques.