EpiPen Shelf Life and Storage
EpiPens have a manufacturer-designated expiration date that is typically 12-18 months from the date of dispensing, and they should be replaced by this date to ensure optimal epinephrine content and efficacy.
Standard Storage and Expiration Guidelines
- Unopened EpiPens should be stored at room temperature between 20-25°C (68-77°F), with brief excursions permitted between 15-30°C (59-86°F). 1
- The manufacturer's expiration date printed on the device represents the period during which full potency and sterility are guaranteed. 2
- EpiPens should never be refrigerated or frozen, and must be protected from direct sunlight and extreme temperatures. 1
What Happens After Expiration
- Research demonstrates that expired EpiPens show progressive epinephrine degradation over time, with bioavailability significantly reduced compared to in-date autoinjectors. 2
- The correlation between decreased epinephrine content and months past expiration is moderate (r = -0.63), meaning degradation is variable and unpredictable. 2
- Studies show that expired epinephrine can maintain chemical concentration and sterility for 30+ months past expiration when stored properly in climate-controlled conditions. 3
Critical Visual Inspection
- Before using any EpiPen, check that the solution is clear and colorless—discoloration (yellowing or browning) or visible precipitates indicate significant epinephrine degradation. 2, 4
- The degree of discoloration correlates well with reduced epinephrine content (r = -0.71), with darker solutions containing less active drug. 4
Emergency Use of Expired EpiPens
If the only available autoinjector is expired but shows no discoloration or precipitates, it should be used in anaphylaxis, as the potential benefit outweighs the risk of suboptimal dosing or no treatment at all. 2
- There are no absolute contraindications to epinephrine in anaphylaxis, and delayed epinephrine administration is associated with fatal outcomes. 5
- Even degraded epinephrine provides some therapeutic effect, which is superior to no epinephrine treatment during life-threatening anaphylaxis. 2
Practical Recommendations
- Patients should be prescribed two autoinjectors and instructed to check expiration dates every 3-6 months, replacing devices before they expire. 6
- Temperature excursions during real-world carrying conditions (in purses, cars, etc.) cause less degradation than previously thought, though prolonged heat exposure accelerates breakdown. 1
- Refrigeration may reduce epinephrine degradation, but freezing effects on autoinjector firing mechanisms are not well-established and should be avoided. 1