Heparin, the miracle drug: a brief history of its discovery.

Heparin is a drug used widely in almost every field of medicine; nevertheless, very little is known about its discovery. Jay McLean, a second year medical student at Johns Hopkins University, discovered this wonderful drug in 1916 while performing research in the laboratory of W.H. Howell, MD. This is a brief account of the story told by Dr McLean before his death.