Storing Insulin and Prefilling Syringes
Insulin can become damaged and ineffective if it is not stored properly.
- Unopened insulin that is packaged in small glass bottles (vials) should be stored in the refrigerator.
- Liquid insulin that is packaged in small cartridges (containing several doses) is more stable. These cartridges are used in pen-shaped devices (insulin pens) with attached disposable needles. Keep unopened pens and cartridges in the refrigerator. After you open them, store them at room temperature.
- Powdered insulin cartridges are packaged in blocks of three on cards sealed in foil. Keep unopened foil packages in the refrigerator. After you open a foil package, use the contents within 10 days. And after you tear off and open a block of three, discard any unused insulin after 3 days.
Always read the insulin package information that tells the best way to store your insulin.
You can keep open bottles with you if you keep them in a dark place. The bottles should not be exposed to temperatures below 36°F (2.2°C) or above 86°F (30°C). Never leave insulin in the sun or in your hot car, because sunlight and heat reduce the strength of the insulin.
Avoid shaking insulin bottles and liquid insulin cartridges too much to prevent loss of medicine strength and to prevent clumping, frosting, or particles settling out. Follow the storage information provided by the manufacturer.
The first time you use an insulin bottle, write the date on the bottle label. Always store an extra bottle of each type of your insulin in the refrigerator.
If you cannot prepare an insulin dose but can give the injection, you may need someone to prepare your insulin dose for you. A family member, friend, or health professional can prefill insulin syringes for you. If you prefill syringes:
- Store the prefilled syringes in the refrigerator with the needle pointing up to prevent insulin from blocking the needle opening. Syringes filled with one type of insulin (rather than mixed insulin) will keep for about a month. Read and follow all instructions on the label.
- Store different doses separately. For example, if your morning dose is different from your evening dose, have a different container for morning and evening injections.
- Before using a prefilled syringe, allow the syringe to warm for 5 to 10 minutes. Gently roll the syringe between your hands to warm the insulin. If the syringe contains a cloudy insulin, make sure all of the white powder is dissolved before giving the shot.
- Another option is to use an insulin pen. You do not have to put insulin into a syringe. You put a cartridge of insulin into the pen. Don't share insulin pens with anyone else who uses insulin. Even when the needle is changed, an insulin pen can carry bacteria or blood that can make another person sick.
- With a disposable pen, a set amount of insulin comes in the pen ready to use. When the insulin is used up, you throw the pen away. You use a new pen the next time you need insulin.
- Before their first use, insulin pens or cartridges are stored in the refrigerator. After that, you can store them at room temperature. They generally expire within a month after you open them. Follow the directions for storing and using the insulin.
Current as of: March 1, 2023
Author: Healthwise Staff
Medical Review:E. Gregory Thompson MD - Internal Medicine & Kathleen Romito MD - Family Medicine & Adam Husney MD - Family Medicine & Rhonda O'Brien MS, RD, CDE - Certified Diabetes Educator & David C.W. Lau MD, PhD, FRCPC - Endocrinology