When Grünenthal’s Thalidomide products were taken off the global market in the early 1960s, it might have seemed the teratogen would never be used again. Yet shortly after it was pulled off the market, it was put back on again.

In 1964 a doctor from Israel, Jakob Sheskin, accidently discovered a side-effect completely unknown up to that point. Sheskin gave one of his leprosy patients some leftover Thalidomide pills, thinking that would help him fall asleep. Not only was his patient able to rest after taking the drug, his skin sores – one of the main symptoms of leprosy – also began to heal.

Just one year later, in 1965, Thalidomide was re-licensed in Brazil for the treatment of ENL (erythema nodosum leprosum – the medical term for the leprous skin lesions). It is still widely used there today and is also the drug of choice in many other parts of the world for the treatment of ENL. The World Health Organization, however, doesn’t recommend Thalidomide for leprosy patients, mainly because of its teratogenic effects and the impossibility to “implement a fool-proof surveillance mechanism to combat misuse of the drug”.