Injectable Insulin for Type 2 Diabetes: When, Why, and How

Getting diagnosed with type 2 diabetes doesn’t make it mandatory for you to take insulin. In fact, most people with type 2 diabetes don’t even need insulin. Only 19 percent of adults with diabetes use insulin, 43% use oral medications, and 15% use both. Some patients can still live healthily by making lifestyle changes and taking oral medications. This applies to patients whose body’s natural insulin production is less but can be managed with oral medications.

However, some people may need additional support by injecting insulin or pump.

When to take injectable insulin for type 2 diabetes?

There is no simple method to determine whether a patient with type 2 diabetes needs insulin therapy. However, there are some guidelines that doctors follow. These are based on assessing the quantity of sugar in your blood.

To check the percentage of sugar, you need to take an A1C test. This measures your system's blood sugar for 2-3 months.

According to primary governing bodies like ADA, AACE, and ACE, A1C levels less than 6.5% are considered safe. Diabetes is diagnosed when the A1C levels jump 6.5%. However, A1C below 5.7% is considered normal.

When you are diagnosed and treated for type 2 medication, your doctor sets for goal for managing your sugar levels.

You will be asked to follow a specific diet and lifestyle and take some oral medications. Generally, insulin therapy is recommended when the patient's hemoglobin A1C exceeds the set goal. The goal set by most doctors is to lower sugar levels below 6.5%.

Why do you need insulin therapy (insulin injection)?

Insulin is a hormone naturally produced by your pancreas. This hormone helps your body to store and use glucose.

The body uses glucose as fuel. When you eat something, it gets absorbed into your digestive tract. Then it transfers to your bloodstream. The insulin hormone lowers blood sugar. This allows the glucose from the bloodstream to your muscles, fat and other cells. Insulin also helps your liver to adjust insulin production when you are fasting.

In type 2 diabetes, the cells don’t respond to the insulin as they are supposed to. This is called insulin resistance. Since glucose can’t reach cells, your blood sugar level rises. As a result, your pancreas starts to work harder to increase insulin production.

For some time, the extra insulin manages to keep the sugar levels normal. However, as time passes, your pancreas can’t keep up with the production. Meanwhile, the blood sugar levels keep getting higher. This leads to Type 2 diabetes. Insulin therapy can help maintain your blood sugar levels when your pancreas can keep up with the insulin production.

How to take insulin injections for type 2 diabetes?

There are several types of insulin available depending on the person’s metabolism.

The types of insulin include

  • Rapid-acting

  • Regular or short-acting

  • Intermediate-acting

  • Long-acting

  • Ultra-long-acting

Your doctor will prescribe you one of the above based on factors such as

Onset − The amount of time it takes the insulin to reach your bloodstream.

Peak time − The amount of time it takes the insulin to reach its maximum effect.

Duration − The amount of time the insulin shows its effect.

Initial insulin dose

Your doctor will likely start with the ‘basal’ insulin. It involves administering the intermediate-acting or long-acting types of insulin. This helps in keeping your blood sugar within levels for a long time, such as throughout the day and over the night.

It is usually administered once a day, either in the morning or before going to bed.

Unlike most medications, the dosage of insulin greatly varies. It can start from a dose as low as 2-10 units to 100+ units. Basal insulin starts with a lower dose of between 10 to 20 units and increases accordingly.

Adjusting insulin dose

Blood sugar levels are frequently checked by the doctor to make an adjustment to your daily insulin dose. You can do that with a home glucose meter in the morning on an empty stomach. Your doctor will increase the dose if your sugar levels remain higher than your fasting blood sugar goal.

If the basal insulin therapy doesn’t work adequately, your doctor may give more than two insulin doses per day.

Temporary insulin

Insulin dosage can be temporary in certain cases. Meaning you can continue taking your regular diabetes medication once the dosage is complete.

Sometimes your blood sugar level may increase due to certain medications. For instance, steroids like prednisone can shoot up your sugar levels. In such events, your doctor will temporarily administer insulin shots as long as you are taking steroids.


Sometimes, oral drugs may work at first to control blood sugar. However, the effectiveness starts to wear off after a couple of years. The truth is diabetes (both type 1 and 2) is progressive. Therefore, patients need to change their treatment over time. Some may need to switch to insulin injections around years into their condition. Some pay needs them temporarily, and some might need them for long term.

Updated on: 12-Apr-2023


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