What is the danger of using insulin that has expired?

Insulin manufacturers test their products to ensure they work as promised, but they also include an expiration date. While products don’t suddenly go bad the moment the expiration date passes, manufacturers cannot guarantee that the insulin will work as promised past that date.

Once insulin is past its expiration date, it is possible that the potency of the product will change, and it is impossible to know at which point in time that will happen. If your insulin is not at full potency, your dosage may be thrown off and complications may occur.

Can expired insulin hurt you?

Yes, expired insulin can hurt you, as it may increase your blood glucose levels. High blood sugar, also called hyperglycemia, comes with harmful side effects and serious complications such as nerve and organ damage. However, the more dangerous risk of using ineffective insulin is diabetic ketoacidosis (DKA), which is fatal if untreated.

Expired insulin side effects

Side effects of using old insulin may include:

  • Thirst
  • Fatigue
  • Blurred vision
  • Frequent urination
  • Nausea
  • Faintness

If you experience any of these symptoms after using expired insulin, check your blood sugar levels and contact your doctor if necessary.

How do you dispose of expired insulin?

The safest way to dispose of insulin that is past its prime is to return it to the pharmacy. Though many pharmacists collect expired medication, not all do, so it is best to inquire in advance. If you cannot find a local pharmacy that collects expired insulin, your doctor or diabetes educator will be able to help.

Doctor’s Recommendation

Scenario 1: Insulin is stored correctly, and the patient’s diabetic glucose ranges are normal under typical diabetic ranges.

Use the expired insulin and monitor its effect, as there may be little change in potency over time and monitor.

Scenario 2: Insulin is not adequately stored for an extended period, AND glucose is approaching DKA levels.

They should avoid using the medicine if their glucose is exceptionally elevated, and if available, they should take an unexpired vial of medicine first. If unexpired insulin is unavailable, inject the imperfect expired insulin and travel to the hospital for precautionary measures.


Disclaimer: Please note that the contents of this community article are strictly for informational purposes and should not be considered as medical advice. This article, and other community articles, are not written or reviewed for medical validity by Canadian Insulin or its staff. All views and opinions expressed by the contributing authors are not endorsed by Canadian Insulin. Always consult a medical professional for medical advice, diagnosis, and treatment.