Insulin is a hormone that helps regulate blood sugar levels. For insulin to work properly, it must be kept at the right temperature. If insulin gets too warm or too cold, it can become less effective. So how long can insulin stay warm before it goes bad?
Quick Answers
– Unopened insulin vials or pens should be stored in the refrigerator between 36°F to 46°F (2°C to 8°C).
– In use (opened) insulin vials or pens can be kept at room temperature below 86°F (30°C) for up to 28 days.
– Insulin should not be frozen or exposed to excessive heat above 86°F (30°C).
– Heat can degrade insulin, making it less effective. Try to keep insulin as cool as possible.
– If insulin gets warmer than 86°F (30°C), it should be discarded after 28 days, even if unopened.
Insulin Storage When Not in Use
When insulin is not being actively used, such as a new, unopened vial or pen, proper storage is crucial for maintaining the drug’s potency. The manufacturer and FDA recommend storing unused insulin in the refrigerator between 36°F to 46°F (2°C to 8°C).
At these cool temperatures, insulin maintains full potency for the entire shelf life printed on the label. For example, if the expiration date on your insulin is 6 months from the manufacture date, storing it between 36°-46°F will keep it effective for the full 6 months.
Refrigeration helps slow down the chemical breakdown of insulin. Keeping insulin too warm speeds up the degradation process, reducing the drug’s potency and effectiveness over time.
Room Temperature Insulin Storage
Once an insulin vial or pen is opened and being actively used, it can be kept unrefrigerated at room temperatures up to 86°F (30°C) for up to 28 days. Room temperature storage makes insulin more convenient for people with diabetes to use throughout the day.
However, it’s important to remember that warmth still degrades insulin more quickly than refrigerated storage. Try to keep in-use insulin away from direct heat and sunlight to maintain its potency for the full 28 days unrefrigerated.
Here are some room temperature guidelines for opened insulin:
- Up to 86°F (30°C) – lasts up to 28 days
- Over 86°F (30°C) – discard after 28 days
To maximize stability, it’s best to refrigerate in-use insulin when possible, such as overnight. Just take out what you need for the next day so it can come to room temperature before injecting.
Avoid Freezing Insulin
On the other end of the temperature spectrum, insulin should never be frozen. Freezing causes insulin molecules to form crystals that can damage the structure of the insulin. This makes the insulin less effective or possibly ineffective at lowering blood sugar.
Vials or pens that have been previously frozen should be discarded, even if never opened. The freezing process irreversibly changes the insulin.
If you ever experience a freeze-thaw incident, always err on the side of safety and throw away affected insulin. Trying to use insulin after freezing could lead to unpredictable changes in blood sugar.
Avoid Excessive Heat
In addition to freezing, exposing insulin to excessive heat above 86°F (30°C) can accelerate degradation. Heat denatures insulin proteins, progressively reducing the drug’s potency and duration of action.
Some examples of situations that generate high heat include:
- Leaving insulin vials or pens in direct sunlight
- Leaving insulin in a hot car for extended periods
- Warmer climates or vacation destinations
If your insulin gets exposed to excessive heat, it may still be usable but its effectiveness could decline faster. Be extra diligent with monitoring blood sugar and watch for any changes in expected insulin action.
And remember, once an opened vial or pen surpasses 28 days unrefrigerated, it must be discarded to avoid potential use of degraded insulin.
How to Tell if Insulin Has Spoiled
The potency of insulin steadily declines outside of ideal storage conditions. But how can you tell if your insulin has spoiled and is no longer good to use?
Watch for these signs of insulin degradation:
- Cloudiness – Insulin normally appears clear and colorless when fresh
- Clumping – You may see particles floating in spoiled insulin
- Frosting on the vial – Development of ice crystals indicates freezing
- Color change – The insulin solution may turn yellow or brown
- Odors – An altered smelly odor could signal chemical breakdown
Additionally, your body provides clues if you’ve been using bad insulin:
- Blood sugar levels are unexpectedly high or low
- Insulin doses that normally work provide little effect
- Hypoglycemic or hyperglycemic symptoms occur suddenly
If you observe any oddities in your insulin’s appearance, potency or expiration date, it’s safest to stop using it and get a replacement.
Proper Disposal of Used or Expired Insulin
When it’s time to throw out used insulin, either due to hitting the 28 day room temperature limit or passing the expiration date, proper disposal is important.
Used insulin needles, pens and syringes can be dangerous if disposed of improperly. Follow these steps for safe disposal:
- Never throw loose needles, pens or vials in the trash or recycling bin, as they could injure sanitation workers
- Place used sharps in a sealable puncture-proof container, like an approved sharps container from your pharmacy
- Take sealed containers to a hazardous waste disposal location or medical waste pick-up service
- Some pharmacies offer free used sharp container collection programs
- Never attempt to reuse or share used needles
As for unused insulin, the best method is to take unopened but expired vials or pens back to your pharmacy for proper disposal.
Keeping Insulin Effective
Storing insulin properly is key for maintaining its potency and effectiveness at controlling blood sugar levels. While opened insulin can stay warm up to 28 days at room temperature, cool refrigeration between 36°-46°F (2°C-8°C) is always best for preserving insulin quality.
Be diligent with discarding insulin that surpasses its room temperature limit, avoiding excessive heat or freezing. And monitor for any signs of insulin degradation like cloudiness or reduced efficacy.
With proper storage and rotation of insulin, you can help keep it working successfully to manage your diabetes.
