Examples

The different types of insulin are categorized according to how fast they start to work (onset) and how long they continue to work (duration). The types now available include rapid-, short-, intermediate-, and long-acting insulin.

Rapid-acting

Short-acting

Intermediate-acting

Long-acting

There are premixed rapid- and intermediate-acting insulins, including:

• 70% intermediate-acting (NPH) and 30% short-acting regular insulin, called 70/30 insulin.
• 50% intermediate-acting (NPH) and 50% short-acting regular insulin, called 50/50 insulin.
• 75% intermediate-acting and 25% rapid-acting Humalog (lispro), called 75/25 insulin.
• 70% intermediate-acting and 30% rapid-acting NovoLog (insulin aspart), called NovoLog Mix 70/30.

Packaging

Injectable insulin is packaged in small glass vials (bottles) and cartridges that hold more than one dose and are sealed with rubber lids. The cartridges are used in pen-shaped devices called insulin pens.

How insulin is taken

Insulin usually is given as an injection into the tissues under the skin (subcutaneous). It can also be given through an insulin pump, an insulin pen, or jet injector, a device that sprays the medicine into the skin. Some insulins can be given through a vein (only in a hospital).

Research is ongoing to develop not only new forms of insulin but also insulin that can be taken in other ways, such as by mouth.

How It Works

Insulin lets sugar (glucose) in the blood enter cells, where it is used for energy. Without insulin, the blood sugar level rises above what is safe for the body.

Your body uses insulin in different ways. Sometimes you need insulin to work quickly to reduce blood sugar. Your body also needs insulin on a regular basis to keep your blood sugar within a target range.

• Rapid-acting and short-acting insulins reduce blood sugar levels quickly and then wear off.
• When you use long-acting insulin with rapid- or short-acting insulins, the long-acting insulin starts taking effect when rapid- or short-acting insulins begin to wear off. The long-acting insulin glargine (Lantus) starts to work within 1 to 2 hours after it is given and continues to work at the same rate for about 24 hours. Lantus cannot be mixed in the same syringe with other types of insulin.
• Usually people who take insulin use a combination of a rapid- or short-acting and an intermediate- or long-acting insulin. This helps keep blood sugar levels within a range that is safe for the body throughout the day.