If you have type 1 diabetes, insulin therapy is an integral part of your treatment plan, as it replaces the insulin your body can’t produce on its own.

And if you’ve been diagnosed with type 2 or gestational diabetes and other therapies haven’t kept your blood glucose levels in the target range, your doctor may recommend making insulin therapy part of your treatment as well.

What is insulin therapy?

The goal of insulin therapy is to keep your blood sugar levels within your target range. There are many different types of insulin and ways to deliver it to your body. Finding the routine that works for you depends on what type of diabetes you have, how much and how often your blood glucose fluctuates during the day, and your lifestyle.

What types of insulin are available to treat diabetes?

Insulin is grouped by how quickly it begins to work, when the insulin in your blood is at its peak, and how long the effects last.

  • Rapid-acting insulin begins working within 10 to 30 minutes, reaches peak effectiveness within 30 minutes to three hours, and lasts for three to five hours. Rapid-acting insulin is sold under the brand names Humalog, Novolog, and Apidra. Use rapid-acting insulin before a meal to cover the rise in blood sugars you'll receive from your food.

  • Regular- or short-acting insulin begins working within 30 to 60 minutes, reaches peak effectiveness within two to five hours, and lasts for up to 12 hours. Short-acting insulin can also be used before a meal; aim to take it about 30 minutes before you eat.

  • Intermediate-acting insulin, also known as NPH, begins working within one and a half to four hours, reaches peak effectiveness in four to 12 hours, and lasts for up to 24 hours. Intermediate-acting insulin is most commonly combined with rapid-acting or short-acting insulin to help cover the blood glucose elevations once the shorter-acting insulins wear off. It's usually taken twice a day.

  • Long-acting insulin begins working within an hour to four hours, has a minimal peak, and lasts for up to 24 hours. Long-acting insulin is sold under the brand names Lantus and Levemir. This type of insulin is usually combined with the short-acting insulins and taken once or twice a day.

Some people may need more than one type of insulin. Others may need a combination of insulin and diabetes medications to help the insulin work effectively. Your doctor will inform you about the medications you need—keep in mind that diabetes is a highly personal disease, so what works for a friend or family member may not work well for you.

Find the right delivery system

Insulin may be injected into a vein or under the skin. There are three main insulin delivery options to choose from, including a pen, a pump, or a syringe. There is also the jet injector, which is a newer way of getting insulin into your body, as well as insulin you can inhale.

Keep in mind that your choice of insulin delivery may be determined by what your insurance will cover. Aside from your medical coverage, base your decision on the system that you’re most comfortable with.

Here’s what you should know about insulin delivery systems so you can choose the one that’s right for you:

Insulin syringe

The syringe uses a very thin needle to inject insulin just under your skin.


  • Flexibility. You can use syringes with almost any type of insulin, and there are plenty of different brands and varieties from which to choose.
  • Inexpensive. At $10 to $15 for a box of 100, syringes are an inexpensive choice, and they’re more likely to be covered by your insurance.


  • Time. There are a few more steps to take when using a syringe. For example, before use, you must fill it with air, attach the needle, and draw the right dosage amount of insulin into the syringe.
  • Dosing errors. Because it’s a completely manual delivery system, you must make sure you’re injecting the right dose.

Insulin pen

An insulin pen works similarly to a syringe. Pens come in either reusable or disposable versions. The reusable type uses an insulin cartridge that is inserted into the pen, while the disposable pens are pre-filled with insulin. Two injections are necessary if you're using two different types of insulin.


  • Easy and convenient. Pens are easier to use than syringes. You simply dial the correct insulin dose on the pen and press a plunger on one end to inject the insulin through a needle at the other end.
  • Memory. A memory feature on the pen tells you how much insulin you used and when you took it.


  • Cost. Ranging from $30 to $40 apiece, insulin pens cost more than syringes, and some insurance companies won’t cover their cost.
  • Fewer options. Not all types of insulin are available in the insulin pen.

Insulin pump

Close to the same size as a pager, you can attach the pump on a belt or put it in your pocket. It delivers a steady stream of insulin 24 hours a day through a flexible, plastic cannula that is inserted under the skin and is attached to a plastic tube. A button on the pump lets you give yourself an extra boost of insulin whenever you eat.

The pump is a good option for people with a very active lifestyle and for individuals with type 1 diabetes who haven’t reached their target blood sugar levels using the pen or syringe. There are still questions about whether the pump can help people with type 2 diabetes.


  • Steady insulin stream. The pump is designed to mimic how the body makes insulin. It constantly delivers a small amount of insulin all the time, with a boost at mealtimes. It’s so efficient that you end up using less insulin than you would with a pen or a syringe.
  • Easy to use and monitor. You don’t have to give yourself injections timed throughout the day because the pump automatically does it for you. Some pumps even wirelessly communicate with your glucose meter, making it easy to adjust your insulin dose based on your blood sugar levels.
  • Better control of blood sugar. Because the pump delivers a steady stream of insulin, it can help avoid drastic blood sugar swings.


  • Constant companion. The downside is you’re attached to a device that you depend on all the time, even when sleeping.
  • Some risks. It’s important to change the needle every few days to reduce your risk of infection. You also must keep an eye on glucose levels, as your blood sugar may be more prone to dropping with the pump than with the pen or syringe. If the catheter slips out or the pump fails, you may not get the insulin you need and blood sugars could increase with time, resulting in serious problems.
  • Cost. Pumps are expensive, ranging from about $5,000. Plus you have the constant cost of supplies like batteries and sensors.

Jet injector

Instead of using a needle, jet injectors use a high-pressure fine spray to push insulin through the pores of your skin.


  • No needles. If you don’t like needles, the jet injector is another option.


  • Ouch! Surprisingly, for some people, the jet injector is more painful than using a needle. This may be due to the high density of nerves near the skin’s surface.
  • Inaccurate dosage. Dosages may not be as accurate because insulin is delivered through the pores rather than directly into the bloodstream.

Inhalable insulin

Afrezza, developed by biopharmaceutical company MannKind, is a mealtime insulin you inhale right when you eat. It's a powder-like insulin that comes in little cartridges that are put into an inhaler. Once inhaled, the insulin is absorbed into the body via the lungs, which contain millions of tiny channels that enable the medicine to move into the blood within five to six seconds.


  • You can inhale the minute you start eating and see peak insulin within 12 to 15 minutes. Within 180 minutes, it’s all out of your system.


  • Lack of flexibility. The product provides only four-unit cartridges in blue and eight-unit cartridges in green. You may be more accustomed to making much smaller adjustments to the amount of insulin you take.
  • It's not for everyone. Afrezza has not yet been tested in children and is not made for people who have serious asthma or other lung diseases.

Talk to your doctor about which insulin options might be best for you. And if you want to try something new, just ask! See what he or she has to say about what's available and what might help improve your blood sugar control.

Other related resources:

Insulin Routines,” American Diabetes Association.

Joslin Diabetes Center, Insulin A to Z: A Guide on Different Types of Insulin