I dont have acne prone skin but i tend to get one or two pimples just before periods and they leave spots which are really annoying. How to prevent them. My dermat prescribed tretinoin 0.04% to be applied on whole face once a week. I also have uneven skin tone and a bit of textured skin on forehead. I wanted to know how do i incorporate tretinoin in my skin care regime mainly to prevent acne before periods and then to adrdress other concerns like uneven skin tone n textured skin. Pls help. Ps...i have normal weight with regular periods...no pcos.