Insulin has been patented for more than 90 years because of incremental improvements made by its manufacturers, according to a study that was published in the March 19 issue of the New England Journal of Medicine. 


Without insurance, insulin costs $120 to $400 per month, which can be a substantial barrier to many patients with diabetes who already consider taking the drug inconvenient. This can lead to lapses in compliance and consequent complications of uncontrolled diabetes.


Authors Jeremy Greene, MD, PhD, and Kevin Riggs, MD, MPH, found that pharmaceutical companies have made a series of improvements that have kept insulin patented and off the generic market since they were given the right to manufacture the drug in 1923.

Biotech insulin is now the standard in the United States, and although patents on the first synthetic insulin expired in 2014, these types of insulin are difficult to copy, will require a lengthy FDA approval process, and will be more expensive to manufacture, the authors wrote. 


“The history of insulin highlights the 
limits of generic competition as a framework for protecting the public health,” said Dr. Greene.