Insulin is very sensitive to sunlight, indoor lights, and to extremely hot or cold temperatures.
Insulin is not OK to use if exposed to very hot or cold weather. The three drug manufacturers of insulin in the United States say UNOPENED insulin is best stored inside the fridge [2° to 8°Celcius (36° to 46°Fahrenheit)]. UNOPENED insulin stored in the refrigerator is good until the expiration date printed on the insulin box. The expiration date will usually be 1 year from the date of purchase but you have to check the box to find out
Once open there are different storage needs for insulin. What does OPEN mean? This does NOT mean removed from the box. OPEN means the insulin cap is removed and the rubber stopper was punctured.
Vials and pens have different needs for storage. These differences can lead to confusion. Therefore, it is very important for you to become familiar with the recommendations for the insulin product that you use.
Vial: Once the vial is punctured, it is OPEN. Once you stick a needle in the vial, it is OPEN. OPEN vials can be stored in the fridge or at CONTROLLED room temperature. Regardless of where it is stored, OPEN insulin will only last 28 days before it must be thrown away. Insulin kept in the fridge should be removed and allowed to reach room temperature before injection.
PEN: Once used for the first time, insulin pens should not be stored in the fridge. Instead, they should be stored at CONTROLLED room temperature. The number of days you can use the pen will depend on which pen you use. Talk to your doctor or pharmacist. Pens last 7-28 days if stored at CONTROLLED room temperature. The number of days depends on which pen you use.
Do not keep in hot places. Do not leave insulin in a hot closed car. Heat makes insulin break down and will not work well to lower your blood sugar.
Do not keep in freezing places. Never store in a freezer. If insulin is frozen, do not use. You will not be able to inject the insulin if it is frozen. Do not use even after thawing. Freezing temperature will break down the insulin and then it will not work well to lower your blood sugar. Throw frozen insulin in the garbage.
Do not leave in sunlight. Light can make insulin break down and then it will not work well to lower your blood sugar.
Never use insulin if expired. The expiration date will be stamped on the vial or pen. Remember if not in the fridge, the date on the vial or pen does not apply. You must throw away after 28 days since outside the fridge.
Write the date on the insulin vial on the day you open it or start keeping it outside the fridge. This will help you remember when to stop using it. Throw the insulin away 28 days after opened or since kept out of the fridge.
Inspect your insulin before each use. Look for changes in color or clarity. Look for clumps, solid white particles or crystals in the bottle or pen. Insulin that is clear should always be clear and never look cloudy.