Insulin Basics – Storing, Drawing, and Injecting

How To Store Insulin

  • Store insulin you are not using in a refrigerator. It is a protein dissolved in water, sort of like soup stock, so keep it cold to prevent it from spoiling. Keep it between 36º and 46º F. If it gets colder it will freeze. If the insulin freezes, when it thaws it will separate and clump and will no longer be usable. If it gets warmer it will be ok for a while but will eventually spoil.
  • If it starts to spoil, bacteria growing in it breaks down the insulin. It won’t hurt you to use this. However, it is not as effective so your blood sugar will be higher than you expect even though you took the right amount of insulin at the right time.
  • It is ok to keep a bottle of insulin you are using at room temperature for up to 28 days (room temperature is 59º to 86º F). The preservative in insulin keeps it from spoiling this long.
  • Insulin at room temperature injected into the skin is more comfortable for many people. Also, it may be easier to get rid of air bubbles in the syringe when it is at room temperature.
  • If you live in a hot climate and your room temperature is above 80º, keep your insulin in the refrigerator.
  • Insulin in a pen can only be kept at room temperature for 2 weeks before it begins to spoil. Check with your pharmacist, the package insert, or the manufacturer’s websites.
  • Insulin used past 28 days at room temperature or past the expiration date on the box may still be good. However, using it may cause control problems and is not recommended.
  • Lantus, Humalog, and Novolog seem to spoil faster than Regular and NPH.
  • If you can’t afford to buy insulin and insurance does not cover it, you may be able to get it free. Check the website www.helpingpatients.org or call 202-835-3400. The doctor who prescribes your insulin can help you get signed up for free insulin.

How To Draw Insulin

  • When you use NPH, Lente, or Ultralente insulin, roll the vial between your hands ten times before drawing the insulin into the syringe. These insulins look cloudy in the vial because particles settle out of the liquid and collect at the bottom. Rolling mixes them so the concentration of insulin you take out is the same all the way through the vial. Don’t shake the vial because this makes a lot of bubbles, which can end up in your syringe keep you from getting your full dose of insulin.
  • Roll prefilled syringes of these insulins to mix the particles back in the insulin.
  • Roll an insulin pen containing NPH ten times. Also, point it up and down ten times. The pen has a tiny glass ball that rolls back and forth when you do this and fully mixes the layers of insulins.
  • Inject air into the vial before you draw the insulin out. The air replaces the insulin you are going to take out. If you don’t put air in, a vacuum is created when you take insulin that makes it hard to pull the plunger out.
  • An insulin pen works differently than a syringe. When you set the dose on your pen, you are telling the plunger how far to move. When you deliver the insulin, the plunger moves forward making the space the insulin is in smaller.
  • Do not mix Lantus in a syringe with any other insulin. The action time of Lantus changes and becomes unpredictable when you mix it.
  • You can give an injection of Lantus at the same time as an injection of Humalog or Novolog in two different syringes in two different locations of the body.

How To Inject Insulin

  • Vary the sites you inject insulin into. If you inject it into the same spot repeatedly, it can cause changes in the fat tissue under the skin. It can cause a pit under the skin where the fat deteriorates or a lump or bump under the skin where extra fat tissue grows. These can change the absorption time of insulin and many people don’t like the way they look.
  • Rotation of injection sites among parts of the body is not recommended as it used to be. Insulin is absorbed more consistently from the abdomen so this is the area to use for injections.
  • Inject at least an inch away from the previous site to avoid pit and bump problems. If you can’t keep track of your injection sites, then imagine lines drawn vertically and horizontally through your navel. Now divide each of these four rectangles into two parts by drawing 2 more vertical lines. Assign each of these 8 squares a day of the week and rotate injections in a particular square on a particular day.
  • Pinch up some skin and fat to inject into to avoid hitting a muscle. If you hit a muscle, it will likely hurt and it could cause a low blood sugar as the insulin is absorbed quickly.
  • Injecting at either a 45º or a 90º angle is correct for most people. For small children and thin adults, the 45º angle is better for assuring the insulin goes into the fat under the skin and not the muscle or they can use shorter insulin needles.
  • Don’t bother to wipe the skin with alcohol or soap & water if the are you inject is kept covered and basically clean. You can inject it through your clothes if you like.

Contact the insulin manufacturers at the following websites and customer service numbers.

Aventis: www.lantus.com – 866-452-6887
Eli Lilly: www.lillydiabetes.com – 800-545-5979
Novo Nordisk: www.novonordisk-us.com – 800-727-6500


Pumping Insulin provides much more pump information and is the most helpful book ever written on insulin use.

Using Insulin takes you step-by-step toward excellent control. Whether you use one injection and pills, or six injections, you’ll learn far more from this book than from any other!