Highly addictive painkiller and illegal narcotic
In 1806 the German chemist F.W.A. Sertürner isolated morphine from opium, a milky substance found in unripe seedpots of the poppy plant. Morphine is one of the strongest naturally occuring painkillers and of great importance where other analgesics fail (for example in cancer management). Side effects include depressiveness, drowsiness and a slowing down of breathing and circulation.
Morphine is addictive. The attempt to find a non-addictive replacement led to the development of heroin, a morphine derivative, by the German chemical company Bayer in 1898. The pain-controlling and analgesic properties of heroin are much more effective than those of morphine, and for over two decades the use of heroin was promoted to the general public against headache and other minor pain. It soon became obvious that it is even more addictive than morphine, and heroin was banned progressively from 1924 onward.
The illegal heroin trade and use causes problems to modern societies, particularly to the Western civilization.

An advertisement for Heroin as cough medicine
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