What is Percocet? Percocet is a pain reliever that contains oxycodone as well as acetaminophen. Oxycodone is an opioid pain reliever. Acetaminophen, on the other hand, is a less potent pain reliever that enhances the effects of oxycodone. Important Information If you have recently used sedatives, alcohol, tranquilizers, or other opioid medications, you should not take Percocet.