Insulin: Who Needs It and Who Doesn't?

Different Insulin Needs for Type 1 and Type 2 Diabetes

Girl holding a syringe with insulin
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Does getting a diagnosis of diabetes automatically mean you will need to start taking insulin? The answer depends on the type of diabetes and how much your condition has progressed.

People with type 1 diabetes require supplemental insulin because their bodies can no longer produce insulin themselves. However, type 2 diabetes is different. Less than one-third of those with type 2 diabetes take insulin.

The CDC puts the number at about 28%. Some experts have long believed that more patients with type 2 diabetes should be on insulin in order to reach their blood glucose and lipid (cholesterol) targets.

When you are diagnosed with type 2 diabetes you will probably wonder if -- or when -- you will need insulin. You may fear injections. You may believe that needing insulin represents a personal failure, so you resist taking the drug, even when you need it. Whether or not a person with type 2 diabetes needs insulin is based on individual circumstances. The first step? Knowing the facts.

Does Everyone with Diabetes Need Insulin?

Type 1 and type 2 diabetes are conditions in which  you don't have enough insulin or don't react to it well enough to remove glucose from the blood. This creates two problems: high blood glucose levels and a lack of stored glucose, the body’s major fuel source.

The difference between type 1 and type 2 diabetes lies in the cause of this condition.

Beta cells, found in the pancreas, produce the body’s insulin. In type 1 diabetes, most of those beta cells have been destroyed, limiting the supply of insulin. As a result, individuals with type 1 diabetes must take insulin to control their blood glucose levels.

In type 2 diabetes, the pancreas may still produce insulin, but it either produces insufficient amounts or the body resists the insulin itself.

Diet, exercise and various oral medications can help the body use its self-produced insulin more efficiently. Here’s the catch: Type 2 diabetes is a progressive disease, meaning the insulin-producing beta cells deteriorate over time. Eventually, actual insulin therapy (in the form of injections) may become necessary.

Insulin Treatment: What Are the Options?

There are more than 20 types of insulin sold in the United States. These products differ in how they are made, how they work in the body and how much they cost. Using any insulin requires attention to at least three variables: onset (the time before the insulin begins to act), peak (the point at which insulin is most effective) and duration (how long the insulin is effective in the body).

Based on the goals and structure of a patient’s management plan, a health care professional may prescribe rapid-, intermediate- or long-acting insulin. Among these categories, insulin onset can begin as soon as 10 to 15 minutes or as long as six hours after injection. Insulin can remain effective for up to 24 hours. Some people who have trouble dosing for themselves use a pre-mixed product of different types of insulin.

Using Insulin

Different delivery options are also available.

Traditional insulin therapy uses injections, either via syringes or insulin pens. These pens can be easier to use than syringes and look very much like writing pens. Frequency and dosing depend on glucose levels and the type of insulin prescribed.

Patients can also use insulin pumps or inhaled insulin. A pump provides a continuous delivery of rapid-acting insulin through a catheter under the skin. The constant flow delivered by the pump is called the basal rate. At mealtimes, or at other times when patients want to take insulin to cover snacks or to “correct” blood glucose levels, the user programs the pump to deliver an additional dose, called a bolus.

A newer product, inhaled insulin, is a short-acting substance inhaled before meals or snacks. It eliminates injections, at least for short-acting insulin, but it’s not as precise as injections. The long-term health risks, if any, are unknown.

When Will a Patient Progress from Oral Medications to Insulin?

Some people can control type 2 diabetes with a well-balanced diet and regular exercise. However, persistently high blood glucose levels probably reflect the need for pharmacological treatment.

Traditionally, type 2 patients have begun treatment with an oral medication, but this has begun to change in recent years. Today, if someone’s A1c level (a test that measures average blood glucose over the last few months) is over 7%, his or her health care professional may actually start insulin immediately.

As type 2 diabetes progresses, the pancreatic beta cells gradually lose their ability to produce insulin. Eventually, the patient requires supplemental insulin to manage the disease. The speed at which diabetes progresses — that is, the rate at which beta cell function declines — depends on many factors, including the patient’s weight, genetics, diet and activity level.

It is important for patients to stay in close contact with their health care professionals. According to many experts, if an A1c level is over 7%, that is a sign that the patient should go on insulin.

Are You Worried about Taking Insulin?

Feeling nervous or uncomfortable about starting insulin is very common, but these concerns should not deter you. If used properly, insulin is a life-promoting drug. If the drug makes you skittish, you should talk to your health care team or ask your health care professional for help finding a support group.


Mayfield, M.D., M.P.H., Jennifer and Russell D. White, M.D. "Insulin Therapy for Type 2 Diabetes: Rescue, Augmentation, and Replacement of Beta-Cell Function." American Family Physician 1 Aug. 2004. 489-500. 10 Sep. 2007.


Walsh, P.A., C.D.E., John. "Will Inhaled Insulin Really Take Your Breath Away?" The Diabetes Mall. 2007. Diabetes Services Inc. 10 Sep. 2007. <>.


"National Diabetes Fact Sheet." Diabetes & Me. 09 June 2005. Centers for Disease Control and Prevention. 10 Sep. 2007. <>.

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