According to HealthTap's Dr. James K. Okamoto, it takes 5.5 half-lives of a drug to cycle out of the human body. DailyMed states that the half-life of Norco is 3.8 hours. Therefore, multiplying 5.5 by 3.8, Norco stays in the human body for a total of 20.9 hours.
According to DailyMed, Norco is the brand name for a combination of hydrocodone bitartrate and acetaminophen. It is given as a pain medication. It comes in two strengths: 7.5 milligrams of hydrocodone and 325 milligrams of acetaminophen, and 10 milligrams of hydrocodone and 325 milligrams of acetaminophen. Pills also have a varying amount of inert ingredients as well.