Paracetamol was first synthesized by Harmon Northrop Morse in 1877 or 1878. It was first used clinically in 1893 by the pharmacologist Joseph von Mering, who tested it on humans. However, paracetamol was not widely adopted in medical practice until the mid-20th century, around the 1950s. It was initially introduced as a prescription drug in the United States in 1951 and later marketed more broadly in the 1950s and 1960s.

Key Timeline Highlights:

• First synthesized: 1877-1878 by Harmon Northrop Morse.
• First clinical use in humans: 1893 by Joseph von Mering.
• Commercial availability and increased medical use: 1950s, starting in the US (1951).
• Became a common over-the-counter drug later in the 20th century.

Thus, paracetamol's first actual medical use dates to 1893, but it took several decades more before it became widely used as a common pain and fever reliever.