Beef and pork insulins are no longer produced and sold in the US. Some
diabetics cannot use the synthetic insulins that are now produced,
usually because of allergies involved. Those individuals can order
beef and pork insulins from the UK, but there are many rules and steps
involved in obtaining those insulins. Here are the links you would
need to read:
http://www.fda.gov/Drugs/ResourcesForYou/Consumers/QuestionsAnswers/ucm173909.htm
Back in the '80s when I was diagnosed, I started on pork-derived Regular and NPH. At the time I remember hearing stories of people that became allergic to the beef and pork insulin. I thought all of that would have been fixed when biologically identical bio-engineered insulin, like Humulin, became available at about that same time. Allergies can be a difficult thing to manage. It's interesting to see that beef and pork insulins still find enough users to stay economically viable.
Terry, I know several T1 folks who are allergic to the modern day insulins. If they cannot adjust, and remain allergic, then animal insulins may be their only choice.
I only knew two people that could not tolerate the rapid-acting analog insulins but when they switched to regular human insulin (Humulin-R and/or Novolin-R), the problem disappeared. Animal-sourced insulins tend to be more of a problem in causing lipohypertrophy than human insulins. Most "allergies" to human insulins are not to the insulin itself but to the preservatives and stabilizing agents that are used to extend shelf life. Using animal-sourced insulin should not be a problem for these folks but frequent injection site rotation is much more critical; possibly because of reactions with the foreign proteins involved and the increased risk of lipohypertrophy.
I have not used animal insulin since the late 1980's although I used animal sourced insulin from 1958 until that time. I still have lipohypertrophy particularly in my abdomen despite using modern RNA bacteria/yeast insulins. I am not sure that the source of insulin has made much difference at least in my case in the lipodystrophy associated with insulin injection.