Bayer, the German pharmaceutical company, used to sell heroin. In the late 19th and early 20th centuries, Bayer marketed heroin as a cough suppressant and a non-addictive substitute for morphine. The company began producing and selling heroin in 1898. At that time, it was promoted as a remedy for various respiratory ailments, including tuberculosis and bronchitis, and was even recommended for use in children.

Heroin, or diacetylmorphine, was synthesized by Bayer chemist Felix Hoffmann, who also synthesized aspirin. Bayer trademarked the name "Heroin" and sold it as a patented medicine until the addictive properties of the drug became apparent.

By the early 20th century, medical professionals recognized heroin's potential for addiction and its harmful effects, leading to increased regulation and eventual prohibition of the drug in many countries.

Sources: History.com, PBS, Smithsonian Magazine