Insulin Aspart Expiration After Opening
Opened insulin aspart (NovoLog) vials expire 28 days after first use, regardless of whether stored at room temperature or refrigerated. 1
Storage Guidelines for Opened Vials
Once you open an insulin aspart vial today, you must discard it after 28 days maximum, even if insulin remains in the vial. This applies to:
- Vials stored in the refrigerator (36°F to 46°F / 2°C to 8°C)
- Vials stored at room temperature (below 86°F / 30°C)
The FDA-approved labeling is explicit: "Throw away all opened NovoLog vials after 28 days, even if they still have insulin left in them." 1
Important Storage Considerations
Temperature requirements:
- Keep opened vials below 86°F (30°C) 1
- Avoid freezing - discard if frozen 1
- Protect from excessive heat and direct light 1
Special circumstances:
- For insulin pump use: The timeline is even shorter - discard after only 19 days total (including 7 days in the pump reservoir) 1
- Change pump reservoir insulin at least every 7 days 1
Clinical Context
While the ADA guidelines note that "a loss in potency may occur after the bottle has been opened" 2, the manufacturer's specific 28-day limit for opened vials takes precedence as the FDA-approved standard 1. This recommendation prioritizes patient safety by ensuring consistent insulin potency for optimal glycemic control.
Common pitfall to avoid: Do not rely solely on the printed expiration date on the vial once opened. The 28-day post-opening limit supersedes the manufacturer's expiration date. Mark the opening date directly on the vial to track this timeline.
Recent research confirms that refrigerated multi-dose insulin vials maintain sterility through extended use 3, and thermostability data shows minimal potency loss under proper storage 4, supporting the safety of the 28-day window when storage conditions are maintained.