The history of Acetaminophen dates back to the 19th century. Acetaminophen was first discovered in 1866, when two French doctors named Arnold Cahn and Paul Hepp were looking for treatments for a parasitic infection in one of their patients. They ordered a supply of naphthalene, a common drug during that time, but they mistakenly received a drug known as Acetanilide, which was for pain reliever. After they had tried this on the patient, they noticed that it not only cured pain, but also reduced fevers. Until 1899, the relationship between acetaminophen and Acetamilide was discovered by Karl Morner of Germany. he stated that Acetamilide is metabolize in the body to become Acetaminophen. In 1995, Dr.McNeil introduced this drug as liquid based and was especially for children because it was a flavoured drug. Tylenol is a non-prescription pain reliever and fever reducer manufactured by McNeil Consumer Healthcare. From 1955-1959, Tylenol was given good results of pain relief. It success encouraged McNeil to develop other Tylenol products, then, in 1961, there was solid medication introduced in tablets made just for adults. The progress of this medicine kept enhancing and then was made as chewable tablets in 1973. At the time of 1976, Tylenol was the top best pain killer in US.