Canine Diabetes Wiki

Close-up of Iletin vial-1923. Iletin from Eli Lilly. Beef R/Neutral in varying strengths--not highly purified, nor were there any suspension insulins at the time. Photo is likely ca. 1922-1923.


Comparison of amino acid sequences in canine/porcine, feline, human and bovine insulins.

Bovine means "derived from a cow." An example would be milk. Generally, grocery stores sell cow's (or bovine) milk, but some also sell milk derived from other species, such as goats.

The pancreases of cows are used to make bovine insulin. The pancreases of pigs also are used to make insulin; hence the term porcine and discussions here of porcine insulin.

Amino acid differences[]


Iletin ad-1950 medical journal. Pure beef insulin in U40 (front) and likely U80 strengths. Regular/Neutral, NPH/Isophane and Protamine Zinc/PZI were available then; Lente, Semilente & Ultralente had yet to be marketed.

1975 Lilly JAMA ad

From left-insulins Semilente ("S"), Protamine Zinc ("P"), NPH/isophane ("N"), Regular/neutral/normal ("R"), Lente ("L"), and Ultralente ("U").

For dogs, there are 2 amino acid differences between their own insulin and bovine: positions A #8 and A #10. On the A insulin chain, dogs have Threonine at A #8-cows have Alanine; dogs have Isoleucine at A #10, while cows have Valine.

These insulins are natural and entirely or partly derived from bovine (cow) sources.

Lilly's Iletin I insulins were a mixture of beef and pork; they were 85-90% bovine insulin.

There is no blend of bovine/porcine insulin marketed presently by any pharmaceutical company. The last was PZI Vet, whose manufacturer, IDEXX, purchased the Iletin I PZI formula from Eli Lilly. It is the basis for PZI Vet insulin, but produced in a U40 strength, as opposed to U100.

Many humans also prefer beef-based insulins, which are claimed by some to give a clearer warning of impending low blood sugar than the comparable human GE and analog insulins.

1999 notice [1] of Lilly's discontinuation of Iletin I beef/pork insulins; pure beef was discontinued in 1995.

Bovine Insulins[]

Prescribing information[]

Prescribing information for Bovine Insulins. [4] This shows information for the insulins of CP Pharma; information can also be applied to:Hypurin Vet Neutral, Hypurin Vet Protamine Zinc, Insuvet Neutral, Insuvet Lente, Insuvet Protamine Zinc, U100 BCP PZI, and Summit PZI .

See also porcine insulins.


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