Can I Use the Back-of-the-Fridge Insulin?

A certified diabetes educator weighs in on the wisdom of using a forgotten vial of insulin.

Integrated Diabetes Services (IDS) provides detailed advice and coaching on diabetes management from certified diabetes educators and dieticians. Insulin Nation hosts a regular Q&A column from IDS that answers questions submitted from the Type 1 diabetes community.

Q – I just found insulin that’s been in the refrigerator (unopened, unused), for two years. Is it dangerous for me to use it?

A – I wish I could say it’s fine to use it, but the problem is you’ll never know what you’re getting out of expired insulin, and that can make it more trouble than it’s worth.

Using insulin past the expiration date on the bottle is not clinically recommended, and there’s a reason for that: although it has been refrigerated and unopened, it will not be as potent as it was meant to be. Insulin is not a stable medication, thus the reason it’s only “good” for 28 days after you open a bottle/vial/pen and keep it at room temperature out of the refrigerator. Although insulin’s shelf life is a bit more stable unopened, it’s never recommended to use it past the date on the box. You could be playing potency roulette with a drug therapy that already involves a lot of guesswork.

Contact your prescribing physician and obtain a new prescription. Fill this prescription about a week before your current bottle/vial or pen of insulin is used up or expires so that you can keep up with use without having so large a back-stock. Set a reminder on your calendar on your phone or wall calendar to help you remember when to fill the next prescription. It also can be a good plan to date the bottle/vial/pen of insulin when you initially open it; that way, you won’t have to worry if the insulin has lost its potency for being past its prime.

Integrated Diabetes Services provides one-on-one education and glucose regulation for people who use insulin. Diabetes “coaching” services are available in-person and remotely via phone and online for children and adults. Integrated Diabetes Services offers specialized services for insulin pump and continuous glucose monitor users, athletes, pregnancy & Type 1 diabetes, and those with Type 2 diabetes who require insulin. For more information, call 1-610-642-6055, go to or write

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Jennifer Smith holds a Bachelor’s Degree in Human Nutrition and Biology from the University of Wisconsin. She is a registered and licensed dietitian, certified diabetes educator, and certified trainer on most makes/models of insulin pumps and continuous glucose monitoring systems. She has lived with Type 1 diabetes since she was a child,and thus has first-hand knowledge of the day-to-day events that affect diabetes management.