He named the 'mould juice' penicillin. Later, he would say: “When I woke up just after dawn on September 28, 1928, I certainly didn't plan to revolutionize all medicine by discovering the world's first antibiotic, or bacteria killer.

When was penicillin first used?

The “marvelous mold that saves lives,” as TIME put it, was first discovered by Alexander Fleming in 1928, but more than a decade would pass before the first American patient was treated with penicillin on this day, Mar. 14, in 1942.

What did they use before penicillin?

Arsenicals and sulphonamides, drugs made by chemical tinkering with synthetic dyes, as well as a number of disinfectants made with metal ions toxic to bacteria, such as mercury or copper, were in use well before the introduction of penicillin.