How are the insulins commonly classified?

Nowadays, the insulins available for use are generally classified based on their predicted onset and duration of action, as outlined below.

The common classifications are:

• Rapid-acting analogue
• Short-acting or neutral
• Medium or intermediate and long-acting
• Mixed
• Analogue mixed
• Long-acting analogue
• Ultra long-acting analogue

‘Analogues’ are insulins where the natural amino acid sequence has been modified to either promote faster or slower action than with natural insulin.

Please note that the commercial brand names of the insulin products can vary internationally.

1. Rapid-acting analogue

Insulins where the natural amino acid sequence has been modified to promote faster action than with natural insulin

Should all be taken just before or with food

Onset of action: Within 15 minutes

Duration of action: 3-5 hours

All times can vary from person to person

Types of ‘rapid-acting analogue’:

• Insulin aspart (available as NovoRapid or, in a new faster-acting form, Fiasp in the UK)
• Insulin lispro (available as Humalog in the UK)
• Insulin glulisine (available as Apidra in the UK)

2. Short-acting or neutral

Insulin either human or derived from animals

Should all be taken 20-30 minutes before food

Onset of action: Within 30 minutes

Duration of action: 6-8 hours

All times vary from person to person

Types of ‘short-acting/neutral’:

• Human insulin (available as Actrapid in the UK)
• Human insulin (available as Humulin S in the UK)
• Human insulin (available as Insuman Rapid in the UK)
• Derived from cows (available as Hypurin Bovine Neutral in the UK)
• Derived from pigs (available as Hypurin Porcine Neutral in the UK)

3. Medium or intermediate and long-acting

Should all be taken 30 minutes before food or bed

Onset of action: Within 30-60 minutes

Duration of action: 12-18 hours

All times vary from person to person

Types of ‘medium (intermediate) and long-acting’:

• Human insulin (available as Insulatard in the UK)
• Human insulin (available as Humulin I in the UK)
• Derived from cows (available as Hypurin Bovine Isophane in the UK)
• Derived from cows (available as Hypurin Bovine Lente in the UK)
• Derived from cows (available as Hypurin Bovine PZI in the UK)
• Derived from pigs (available as Hypurin Porcine Isophane in the UK)
• Human insulin (available as Insuman Basal in the UK)

4. Mixed

Mixture of short-acting and intermediate acting insulin in one injection.

Should all be taken 20-30 minutes before food

Onset of action: Within 30-60 minutes

Duration of action: 12-14 hours

All times vary from person to person

Types of ‘mixed’:

• Human insulin, 30% short-acting (available as Humulin M3 in the UK)
• Derived from pigs, 30% short-acting (available as Hypurin Porcine 30/70 Mix in the UK)
• Human insulin, 25% short-acting (available as Insuman Comb 25 in the UK)
• Human insulin, 50% short-acting (available as Insuman Comb 50 in the UK)

5. Analogue mixed

Mixture of rapid-acting analogue insulin and intermediate acting insulin in one injection; ‘biphasic’)

Should all be taken just before or with food

Onset of action: Within 15-30 minutes

Duration of action: 12-14 hours

All times vary from person to person

Types of ‘analogue mixed’:

• Insulin lispro (available as Humalog Mix 25 in the UK)
• Insulin lispro (available as Humalog Mix 50 in the UK)
• Insulin aspart (available as Novomix 30 in the UK)

6. Long-acting analogue

Insulins where the natural amino acid sequence has been modified to promote slower action than with natural insulin

Either can be used once or twice daily as long acting insulin. Can be taken at any time, but at the same time daily

Onset of action: Within 30-60 minutes

Duration of action: 18-24 hours

All times vary from person to person

Types of long-acting analogue:

• Insulin glargine (available as Lantus in the UK)
• Insulin detemir (available as Levemir in the UK)

7. Ultra Long-Acting analogue

Can be used as either once daily or two-three times per week as long acting insulin. Can be taken any time but at the same time daily

Onset of action: Within 30-90 minutes

Duration of action: up to 42 hours

All times vary from person to person

Types of ‘ultra long-lasting’ analogue:

• Insulin degludec (available as Tresiba in the UK)

If you’d like to learn more about insulin, check out the full online course from the University of Southampton, below.