when was tylenol invented?

Tylenol was invented and introduced to the market in 1955 by McNeil Laboratories, Inc. It was initially marketed as Tylenol Elixir for Children and was available by prescription. The active ingredient in Tylenol is acetaminophen, which was first synthesized in 1878 but gained prominence as a safer alternative to aspirin around the mid-20th century. Later, in 1959, Johnson & Johnson acquired McNeil Laboratories and made Tylenol available over the counter.