An Insulin Summary:

This write up is only meant to provide a brief summary of the forms of Insulin now available, it is meant to give the average person, with a non medical background, a general idea of where Insulin comes from and how each form is produced; if a more detailed explanation of Insulin is required there are several other sites that provide this, but for most people this summarised explanation should suffice.

There Are Currently Three Forms Of Insulin:

Animal Insulin, as the name suggests, comes from animals; Human Insulin, as the name suggests, does not come from humans; it is synthetic and made in laboratories and Analogue Insulin, refers to another laboratory grown Insulin, which is genetically altered.

Animal Insulin:

This form of Insulin comes from pigs and cows and was the first type of Insulin to be administered to humans to control their diabetes; up until the 1980s, Animal Insulin was the only treatment for Insulin dependent diabetes; these days however, the use of Animal Insulin has largely been replaced by Human Insulin and Human Analogue Insulin, however, Animal Insulin is still available on prescription.

How Is Animal Insulin Produced?

Animal Insulin is taken from the pancreases of animals, normally pigs (porcine or pork Insulin) or cows (bovine or beef Insulin); the Insulin is then purified which reduces the chance of the Insulin user developing a reaction to the Insulin.

Some examples of Animal Insulin are the Short Acting Insulins (Hypurin Porcine Neutral and Hypurin Bovine Neutral); the Intermediate Acting Insulins (Hypurin Porcine Isophane and Hypurin Bovine Isophane) and the Long Acting Insulins (Hypurin Bovine lente and Hypurin Bovine PZI (protamine zinc Insulin)); Premixed Insulins such as Hypurin Porcine 30/70 are also available these consist of a mix of of Short Acting and Intermediate Insulins.

How Long Does It Take For Animal Insulins To Work?

Short Acting Insulins start to act about 30 minutes after injection, with their peak action occurring within 3 to 4 hours and they last up to 8 hours; Intermediate Acting Insulins take about 4 to 6 hours to start acting, with their peak action occurring between 8 and 14 hours and they last up to 24 hours and the Long Acting Insulins take about 1 hour to start acting, with no peak action occurring and they last up to 24 hours

A disadvantage of using most Animal Insulin is in the peak acting time, which in the Short Acting and Intermediate Insulins occurs at least 3 hours after injection, which can make the timing of meals in relation to injections more difficult than with human and particularly Analogue Insulins.

Human Insulin:

This is alaboratory grown Insulin, which is meant to mimic the naturally produced Insulin from the human pancreas; it was developed through the 1960s and 1970s and finally approved for pharmaceutical use in 1982; Human Insulin is created by growing Insulin proteins within E-coli bacteria 'Escherichia Coli'.

How Long Does It Take For Human Insulins To Work?

Some examples of Human Insulins are (Regular Short Acting Humulin S, Actrapid and Insuman Rapid) and the NPH Intermediate Acting Insulins (Humulin I, Insuman Basal and Insulatard); Premixed Insulins such as (Humulin M2, M3, M5, Insuman Comb 15, 25 and 50) are also available these consist of a mix of Regular and Intermediate Acting Insulins.

NPH (Neutral Protamine Hagedorn) Insulin, also known as Isophane Insulin, is a suspension meaning that the Insulin vial should be rolled or repeatedly turned upside down to ensure the solution is uniformly cloudy.

It has been reported that Human Insulins may lead to unwanted side effects such as loss of hypo awareness, lethargy and weight gain; side effects that do not often occur when taking Animal Insulins.

Analogue Insulin:

This is a sub group of Human Insulin; it is laboratory grown and genetically altered; it is created by growing Insulin proteins within E-coli bacteria 'Escherichia Coli'; the process goes further by changing the order of amino acids to allow the Insulin to be used by the body either more rapidly or more uniformly by the body than with regular Human Insulin; this type of process is known as undergoing ‘recombinant DNA’ technology; therefore, the Insulin is genetically altered to create either a more Rapid Acting or a more uniformly acting form of the Insulin, which can have advantages for blood sugar management; these Analogue Insulins have been available since just before the start of the new millennium and is available in two main forms, Rapid Acting and Long Acting, as well as premixed combinations.

Some examples of Analogue Insulins are Rapid Acting Humalog and NovoRapid; Long Acting Lantus and Levemir and the Premixed Analogue Insulins Humalog Mix 25, Humalog Mix 50 and NovoMix 30; the premixed Analogue Insulins consist of a mix of Rapid Acting and Long Acting Insulins.

How Long Does It Take For Analogue Insulins To Work?

Rapid Acting Insulins start to act immediately after injection, with their peak action occurring within the first hour and they last up to 4 hours; Long Acting Insulins take about 2 hours to start acting, but are designed to act uniformly so that there is no peak activity as such and they last up to 24 hours.

Long Acting Analogue Insulins have become popular partly due to the lack of a peak activity period, which allows for easier prediction of how it acts and gives some people more confidence that they will avoid night time Hypoglycemic attacks; however, as with Human Insulins, it has been reported that Analogue Insulins may lead to unwanted side effects such as loss of hypo awareness, lethargy and weight gain; side effects that do not often occur when taking Animal Insulins; Analogue Insulins also cost the NHS around twice as much as non Analogue Human Insulins.

NB. When injecting Insulin be aware of the fact that repeated Insulin injections in the same area can cause medical problems such as Lipoatrophy and Lipohypertrophy.

Diabetes Related Information Leaflets