The FDA needs to conduct studies to ensure the amount of insulin is exactly the same PER MILLIMETER of fluid in a pen and/or vile. The same patient may need more of an injection if manufacturers are monkeying with the formulation of the insulin vs. carrying fluid. It is one thing to pay $35 per pen or vile and quite another believing one’s diabetes has gotten worse which now requires 2 pens per month or 2 biles per month when only one was necessary before.
It is called capitalism vs. quality control.