In 1888, cough syrup produced in Baltimore contained the following ingredients: alcohol, cannabis, chloroform, and morphine. In less than a decade, Bayer successfully synthesized aspirin and heroin. Heroin, derived from the German word "heroisch" meaning "heroic," was marketed by Bayer as a less addictive cough suppressant than morphine.
If you were to open the 11th edition of the Encyclopedia Britannica from 1910 and look up "morphine," you'd find the following passage: "In the cough of phthisis, minute doses of morphine are of service, but in this particular disease, morphine is frequently better replaced by codeine or by heroin, which checks irritable coughs without the narcotism following upon the administration of morphine."
In 1924, the US Congress banned the selling, manufacturing, and importing of heroin due to its high addiction rate. Bayer lost its trademark rights to heroin and aspirin in 1919, following Germany's defeat in World War 1.