The analgesic action is defined as any process whose goal is pain reduction. It can be not only a medication, but any other method which targets analgesia, meaning the suppression of painful sensations. There are generally 3 classes of analgesic medications with differing actions and affects. Owing to the fact that more unpleasant side-effects arise depending on the class, the most powerful analgesics are only used in the case of pain that persists despite the more common analgesics. Paracetamol, ibuprofen, and aspirin are the molecular analgesics consumed the most often. Morphines that act on the central nervous system are the most powerful, but also come with the most inconveniences. Analgesics can be administered orally, rectally, by local application, or by injection depending on the nature and the intensity of the pain. Certain molecules are not specifically made for analgesia, but have analgesic benefits.