Why do drugs have a shelf-life?

22nd July 2009

Asked by: David Hall, Cambridge

Cynics argue that shelf-lives are just invented by pharmaceutical companies to make us buy fresh batches of perfectly good drugs. In reality, government regulators demand extensive testing to find out how long the compounds retain their potency. When they're kept at room temperature, the molecules that make up the drugs degrade just like foodstuffs - and can, in some antibiotics at least, even turn toxic.


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