Last Updated: 03/15/04 06:40 PM        

Sent: Monday, May 03, 1999 11:13 AM
To: Dave Groves
Subject: Re: Why the beef pork mix??

Hi Dave,

On Sun, 2 May 1999, Dave Groves wrote:

> Does anyone have any idea why they mixed beef (85%) with pork (15%) to  produce Iletin® 1 and called both pork AND beef monocomponent insulins  Iletin® 2? <

I talked to Eli Lilly a couple of years ago about why the mix. It seems that eons ago, when no one had a clue as to differences in activity curves, nor even differences in immuunogenicty between beef and pork, these two insulins were thought to be absolutely equivalent. So they saw no harm in throwing them together in the same vial. However, even as the error in this thinking slowly became apparent, Lilly continued making the blend simply because there were so many people using it successfully who didn’t want to change to pure beef or pure pork.

Finally, the reason for the pure beef and pure pork (Iletin II series) was that there were people who were either (1) totally allergic (breaking out all over their bodies) to beef insulin due to it having three amino acids different from human insulin, which is what the immune system expects to find in the bloodstream, so pure pork was needed here, or (2) they found the activity curves of pure pork insulins so much shorter than beef that they had difficulty getting through the night on pork crystalline insulin without losing control of their blood sugars (me for example), so pure beef insulin was needed.
[see 1986 American Hospital Formulary cite]

Ah, those were the days! An insulin company responding to medical necessity. Gone, as they say, with the horse and buggy.