Types Of Insulin - Insulin Therapy For Type 1 Diabetes: Diabetes A Plan For Living

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Types of insulin

Insulin can be prepared from beef or pork pancreas, or from bacteria or yeasts that have been genetically engineered to make human insulin. Today, the vast majority of insulin used in the United States is human insulin. The various types of insulins can be used alone or in combination to simulate normal insulin secretion and to help you keep blood sugar levels under control. In addition, several new modified forms of insulin offer either a very long duration of action or very rapid onset with a short duration.

While it's possible to estimate when the insulin peaks and how long it may remain active, there's no guarantee that the pattern will remain consistent. A larger dose usually lasts longer than a smaller one, but the absorption of insulin can vary, so intermediate- and long-acting insulins may peak at different times on different days.

Very-rapid-acting insulin. Relatively new, very-rapid-acting insulins work within 15 minutes of injection. They peak sooner than rapid-acting insulin (see Table 3), so you can take them closer to mealtime, but they don't last as long. The shorter duration of these very-rapid-acting insulins is helpful because the lingering effects of rapid-acting insulin can cause episodes of hypoglycemia if the next meal isn't eaten on time. Inhaled insulin is a type of rapid-acting insulin (see "Inhaled insulin"). It needs to be taken about 10 minutes before a meal. In studies, peak insulin levels were achieved 30 to 90 minutes after it was inhaled.

Rapid-acting insulin. Rapid-acting insulin, sometimes referred to as short-acting or regular insulin, starts to lower blood sugar levels about 30–60 minutes after injection. Rapid-acting insulin is clear in appearance and normally taken 30–45 minutes before a meal, with its action peaking in one to two hours and usually lasting five to eight hours.

Intermediate-acting insulin. Intermediate-acting insulin, which is cloudy in appearance, doesn't begin to work until approximately two hours after it's injected. Depending on the medication used, peak effect occurs anywhere from 4–15 hours after injection, although it may remain active for as long as 18–24 hours.

Long-acting insulin. Long-acting insulin has a slow onset and a relatively small peak effect and can last for as long as 36 hours.

Last updated:	January 23, 2007