Overview of Insulin Storage and Safety for People with Diabetes

how to store insulin

Verywell / Ellen Lindner

Proper storage of insulin is vital for making sure it is effective for managing diabetes. As with many medications, insulin can be affected by changes in temperature, sunlight, and other environmental factors. It's important to take certain precautions to protect the quality of your insulin so that it can properly do its job.

How to Store Insulin

Unopened insulin should always be stored in the refrigerator and is good until the expiration date on the bottle. If any of your insulin has expired, it should be discarded—the insulin will no longer be potent or effective. Injecting cold insulin can sometimes be more painful, however, so many practitioners recommend keeping the vial you're using at room temperature. Once opened, insulin can generally last about one month at room temperature (59 to 86 degrees). If you buy multiple bottles, be sure to store any unopened bottles in the fridge.

Check the package insert to assess how long your specific insulin can last at room temperature. Some insulin pens can only last about 28 days. A vial of insulin is considered open if its seal has been punctured. If you remove the cap but don't puncture the seal, the bottle is still considered unopened.

How to Protect Insulin From Heat or Cold

Extreme heat or cold can affect the efficacy of your insulin if it is not stored properly. During the summer months, this can be especially tricky—beach days and barbecues mean you're out and about in the heat and sun. But a few simple tips can help you keep your supply safe and intact.

If you are going to be in the heat, be aware of the following:

  • Don't leave your insulin in a heated car.
  • Don't keep your insulin in direct sunlight.
  • Never freeze your insulin, as this can affect potency.

Instead, aim to:

  • Keep insulin out of direct sunlight: Do not leave it in your open beach bag or on your front dashboard.
  • If you're going to be outdoors for an extended period of time, store your insulin in an insulated case with a cold pack (the FRIO wallet is a good option, but any insulated case will do).
  • Bring an umbrella to keep yourself shaded while administering insulin.

How to Tell If Your Insulin May Be Compromised

Check whether it has an unusual appearance. This is where it's important to know the typical color and consistency of the insulin you take. For example, if it's cloudy when it's supposed to be clear, if small crystals appear, if it's stringy, or if it has clumps even after rolling it between your palms, it's likely that something may be wrong. If you think your insulin has gone bad, don't take any chances: Throw the bottle away immediately and open a new one.

Avoiding Dosage Mistakes

Be vigilant about checking your insulin vial every time you take a dose. Review the label to confirm the name and to make sure you're taking the proper concentration. If you're using two different types of insulin (bolus and basal, for example), you could accidentally cause a hypoglycemic or hyperglycemic episode to occur by administering the wrong dose at the wrong time.

If you've recently changed insulin concentrations and aren't sure how much to take, consult your healthcare provider and/or pharmacist immediately—never guess when it comes to your insulin dosage.

Be sure to use the delivery system that makes sense for the insulin format you're taking, i.e., don't use a syringe with an insulin pen as you may end up with a too-low dose.

Never share insulin vials with someone else. To avoid mix-ups, be sure to store your insulin away from that of others in your home who may also be prescribed insulin.

If you're traveling, be sure to bring a more-than-sufficient supply of insulin with you, as other places (especially other countries) may not have the same concentrations you require for your dosage.

Syringe Reuse

Reusing your syringe can cut down on waste and cost, but most manufacturers don't recommend reusing any syringes, as sterility can no longer be guaranteed and dulling may occur after even one use—making injection more painful. Talk to your healthcare provider about their recommendations for reusing syringes.

If you're currently sick, have a weakened immune system, or have open wounds on your hands, it's best to not risk infection by reusing a syringe. Never share your syringe with another person. Note also that cleaning the syringe needle with alcohol may remove the special coating that helps it enter the skin more easily.

Discarding Syringes and Needles

You'll know it's time to discard your syringe if it's bent, dull, or has come into contact with anything other than clean skin and insulin. Recap the syringe before discarding or safely destroy the needle by using a special clipping device that breaks the tip and catches and contains the needle.

Dispose of used syringes in a specially designed sharps container or empty laundry detergent or bleach bottle, where there's no risk of them poking through the container. If you're traveling, bring used syringes home in a hard plastic container, like a pencil case that closes.

Look into medical waste guidelines in your area, or follow the steps recommended by the Centers for Disease Control and Prevention.

2 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Kaiser Permanente. How to store insulin. January 2019.

  2. Centers for Disease Control and Prevention. Injection drug use and HIV risk. Feb 6, 2020.

Additional Reading

By Barbie Cervoni MS, RD, CDCES, CDN
Barbie Cervoni MS, RD, CDCES, CDN, is a New York-based registered dietitian and certified diabetes care and education specialist.