The race to launch a pill for weight loss

It is hard to assess how large the market for weight-loss pills will become, as drugmakers have already misjudged the size of the obesity market — in both directions. Photo by JJ Van Ginkel/Getty Images/Postmedia files

During the first world war, women working in munitions factories began to dramatically lose weight . These so-called Canary Girls were handling a yellow toxic chemical known as DNP, which sped up their metabolisms and enabled their bodies to burn fats faster.

Soon, drug companies were selling DNP, which is short for 2,4-Dinitrophenol, in pill form. Such was the demand for a weight-loss drug that sales flourished even though in high doses the pills caused cataracts, skin lesions and even death.

From extracts of animal thyroids in the late 19th century to the fen-ph