Hi. The reasons for pimples on the forehead and cheeks are different. The cheeks are the most common area for acne breakouts for people under 20. In some cases, acne breakouts on the cheeks are related to wrong makeup, wrong hair products that are in contact with the side of the face, sleeping on one side, rubbing the face with an un-washed pillow, leaning on the hand or your mobile touching your cheek. The best way to reduce pimples on the cheeks is Try to avoid these acne triggers and in parallel use an effective anti-acne medical grade treatment routine, such as MDacne.