The types of insulin available for clinical use in India can be classified on the basis of their source, strength and time-characteristic of their activity.

Classification based on Source

The insulins available for routine clinical use are the beef, porcine and human insulins.

The beef and porcine insulins are extracted from the pancreas of cows and pigs respectively

Human insulins are made by genetic engineering or by the chemical modification of porcine insulin i.e., by substituting alanine with threonine in the B30 position.

Beef insulins differ from human insulin in three amino acids, whilst porcine insulin differs from human insulin in only one amino acid. Thus, porcine amino acids are less immunogenic than beef insulins.

But the beef insulins continue to be widely used in view of their relatively lower costs.

Human insulins are pure and have the same amino acid structure as that of native insulin.

Human insulins are replacing the other insulins in most developed countries, but its cost is the inhibiting factor to its widespread acceptability in most developing countries.

The insulins available now are the "pure" varieties and contain negligible amounts of contaminants.

Classification based on Strength

The vast majority of the insulins used in India are of the U-40 strength ( 40 units of insulin/ml.

Most of the countries in the world have switched over to the use of U-100 ( 100 units of insulin /ml) insulins.

U-100 insulin are also available for use in India especially for use with insulin delivery devices such as "pens".

• how soon the insulin starts working (onset)
• when it works the hardest (peak time)
• how long it lasts in your body (duration).

However, each person responds to insulin in his or her own way. That is why onset, peak time, and duration are given as ranges.

It is important that each person have a clear understanding of the characteristics of each type of insulin that he/she is taking. When blood sugar levels are not well controlled at certain times during the day, or if reactions are occurring, the knowledge of the action and characteristics of each insulin being taken will help to determine where changes need to be made.

The insulins available for clinical use can be classified as

Rapid acting:



Insulin analogs have been developed by modifying the amino acid sequence of the insulin molecule. This modification alters the time characterisitics of activity. The only insulin analog available in India is the rapid acting Lispro. It reaches the blood within 15 minutes after injection. It peaks 30 to 90 minutes later and may last as long as 4-5 hours.

Short-acting (regular) insulin usually reaches the blood within 30 minutes after injection. It peaks 2 to 4 hours later and stays in the blood for about 4 to 8 hours.

Intermediate-acting (NPH and lente) insulins reach the blood 2 to 6 hours after injection. They peak 4 to 14 hours later and stay in the blood for about 14 to 20 hours.

Intermediate-acting insulins include lente and NPH. Insulin preparations with a predetermined proportion of NPH mixed with regular, such as 70% NPH to 30% regular, or a 50/50 mix are called intermediate acting for purposes of classification, although their activity characteristics would be different from either only NPH/Lente or only Regular insulins.

Long acting;



Long-acting (ultralente) insulin takes 6 to 14 hours to start working. It has no peak or a very small peak 10 to 16 hours after injection. It stays in the blood between 20 and 24 hours.