These early tests of insulin raised an important ethical issue: Who should get insulin? In early 1922, there were probably thousands of diabetic patients within weeks of dying, and hundreds of thousands who were within years of dying, but a very limited supply of insulin. Should the insulin be sold to the highest bidder, given to those with the most money? Those who were closest to dying? The youngest children, who could live the longest? The politically connected? Perhaps it should be first allocated to those who could do the most good for society, like Dr Minot at MGH who was developing a cure for pernicious anemia.
While Banting and Best were working on human trials of their pancreas extract, Macleod foresaw a larger problem. If insulin worked as promised, there would be a tremendous demand for it. Banting’s initial idea, to tie off part of the pancreas and wait two weeks to remove the pancreas and collect the insulin, would not satisfy the demand. Banting had some visions of a slew of surgeons working at a cattle ranch, operating on cows to tie off their pancreatic duct two weeks before they were scheduled for slaughter, but this approach was clearly impractical. Macleod set up several alternative possible methods to obtain insulin. For one, he enlisted a professor of biochemistry, James Collip, to work out a more efficient way to obtain insulin from pancreases.