Insulin is a medication used to treat diabetes. It helps control blood sugar levels by allowing cells to absorb glucose from the bloodstream. Insulin must be kept refrigerated to maintain its potency and effectiveness. But how long does insulin actually last in the fridge? Here is a quick overview of insulin’s shelf life and the factors that impact how long it remains usable when properly stored.
How Long Does Refrigerated Insulin Last?
Most insulin products will last for 28-31 days when stored properly in the refrigerator between 36-46°F (2-8°C). However, some types of insulin, such as Humulin R U-500 concentrated insulin, may only last 14 days when refrigerated.
Unopened vials and pens generally last longer than opened ones. Once opened, the shelf life shortens to the following timeframes for common types of insulin:
– Short-acting insulin (e.g. Humulin R, Novolin R): 31 days
– Intermediate-acting insulin (e.g. Humulin N, Novolin N): 31 days
– Long-acting insulin (e.g. Lantus, Levemir): 28 days
– Pre-mixed insulin (e.g. Humulin 70/30, Novolin 70/30): 10-28 days
So in summary, most refrigerated insulin will stay usable for 28-31 days once opened. Unopened, it can last for years past the manufacturer’s printed expiration date if stored in the fridge.
Does Refrigerated Insulin Go Bad?
Yes, eventually insulin that is kept in the fridge will go bad and no longer work effectively. Signs that your insulin may have spoiled include:
– Cloudiness in the liquid
– Clumping or frosting of the insulin
– Color changes
– The insulin becoming sticky or having particles
If you notice any changes to the normal appearance of refrigerated insulin, it should be disposed of and not used.
Using bad insulin can be dangerous as it may not be fully potent or effective at lowering blood sugars as expected. This could lead to episodes of hyperglycemia after injecting spoiled insulin.
Factors that Shorten Insulin’s Shelf Life
Some factors can shorten the shelf life of refrigerated insulin, causing it to expire faster than the typical 28-31 days after opening:
– Warm temperatures – Any temperature fluctuations outside of 36-46°F could reduce shelf life. This includes leaving insulin out at room temperature for too long.
– Direct sunlight – Exposure to UV light breaks down insulin over time. Keep vials in the fridge out of sunlight.
– Repeated warm-ups – Insulin that is warmed up to room temperature repeatedly will degrade faster. Try to limit syringe warm-ups when possible.
– Damage – Dropping or shaking up insulin vials can damage the proteins and shorten shelf life. Handle vials with care.
– Expired vials – Outdated insulin that has passed the manufacturer expiration date may have less than 28 days of use when first opened.
– Diluted insulin – Mixing insulin with another solution like saline can decrease its potency faster. Only dilute when absolutely necessary.
– Opened pens – Insulin pens in use degrade faster than vials. Discard opened pens after 28-31 days.
– Reusing needles – Dull needles drag on rubber stoppers and introduce contaminants into the insulin each use. Change lancets frequently.
Being mindful of these factors can help your refrigerated insulin last for its full 28-31 day shelf life after first use.
Tips for Storing Insulin to Maximize Shelf Life
Here are some best practice tips for storing insulin in the refrigerator:
– Set fridge at 36-46°F (2-8°C) – This cooler temperature is ideal for insulin.
– Store in center or back of fridge – Steadier temps compared to door.
– Keep vials upright – Prevents leakage from the stopper.
– Don’t freeze – Frozen insulin becomes ineffective and unusable.
– Don’t store near cooling element – Direct contact could freeze insulin.
– Avoid door storage – Exposed to warmer air and temperature fluctuations every time door is opened.
– Protect from light – Store in original box or opaque bag/container.
– Prevent damage – Handle gently, don’t shake or drop.
– Check expiration dates – Use insulin with the furthest from expiring first.
– Discard if discolored, clumpy, frosted, or sticky.
– Wipe vial tops before use – Cleans any dust or moisture that could contaminate insulin.
– Don’t top-off – Never re-enter a vial with a used needle or syringe.
Following these simple guidelines helps maintain the integrity and potency of your insulin supply when refrigerated.
What to Do if Insulin Has Been Left Out
Accidents happen, and sometimes insulin gets left out unrefrigerated. Here’s what the manufacturers recommend in these cases:
– **Humulin and Novolin** – If left at room temperature under 86°F for less than 28 days, insulin may be put back in the fridge for use. If over 86°F or more than 28 days unrefrigerated, the insulin must be discarded.
– **NovoLog** – Can be used if left out for less than 28 days, as long as it’s been under 98.6°F the entire time.
– **Lantus and Levemir** – Discard if left unrefrigerated for more than 28 days or exposed to temperatures over 98.6°F.
– **Apidra** – Can be used if left out up to 28 days at 68-77°F.
– **Humalog** – Can be used if left out up to 28 days at 68-86°F.
In general, do not use insulin that has been warm or kept at room temperature for longer than 28 days. When in doubt, play it safe and replace with a new vial or pen. Never risk injecting insulin that may have lost potency.
How to Store Unopened Insulin
Unopened, unused insulin has a much longer shelf life than opened vials and pens. Here are some storage tips for maximizing the life of unopened insulin:
– Check manufacturer’s expiration date – Typically 2-3 years after production.
– Store in the fridge – Keeps insulin fresh 36-46°F (2-8°C).
– Can also be stored at room temperature – For up to 28 days below 86°F.
– Avoid extreme heat or cold – Should not be frozen or kept above 86°F.
– Protect from direct light – Sunlight and UV rays break insulin down.
– Keep in original packaging – Foil pouches and boxes protect from light.
– Avoid damage – Prevent drops that could destabilize insulin proteins.
– Write date opened on vial or pen – So you know when 28-day clock starts.
– Rotate stock – Use vials and pens with closest expiry dates first.
Stored properly in the above conditions, most unopened insulin has a shelf life of 2-3 years past the manufacturer print date before degrading to less than optimal quality and potency.
How to Dispose of Used Insulin
It’s important to properly dispose of insulin once it has expired or been used up. Here are some safe, recommended disposal methods:
– **Needle clippers** – Clip off the needle tip and dispose in a sharps container. Can throw rest of syringe or pen in the trash.
– **Needle destruction device** – Some pharmacies offer at-home needle destroyers that renders sharps useless.
– **Take-back programs** – Some pharmacies accept used sharps for safe disposal.
– **At-home needle melting devices** – Melt and seal needles at home using an FDA-cleared device.
– **Household sharps container** – Sealable puncture-proof containers to store used sharps for disposal through take-back programs or pickup services.
– **Waste management services** – Some residential waste disposal companies offer medical waste or sharps disposal programs.
Never throw loose sharps or uncapped needles directly in household garbage cans. Always seal in puncture-proof containers before trash disposal. Follow your local regulations for proper medical waste and sharp object disposal.
Signs Your Insulin Has Gone Bad
Be on the lookout for these signs that your refrigerated insulin may have gone bad and needs to be replaced:
– **Discoloration** – Insulin normally appears clear and colorless. Yellow, brown, or cloudy discoloration indicates spoilage.
– **Clumping** – Insulin proteins can clump together into visible particles when degraded.
– **Frosting** – White frosty patches or crystals in the insulin liquid signals damage.
– **Precipitation** – Solid particles settling at the bottom signals instability. Gently swirl before use.
– **Stickiness** – Insulin drying into a sticky, tacky residue on the glass vial is a red flag.
– **Mold** – Any fuzzy mold spots mean the insulin must be discarded immediately.
– **Floaters** – Tiny bubbles or floating particles in the insulin liquid are a sign of contamination.
– **Leaking** – Leakage from vial stopper or cartridge can indicate chemical breakdown.
– **Odor** – Though rare, bad or strange chemical odors could mean deterioration.
– **Foaming** – Agitating insulin that foams up more than usual indicates the proteins are breaking down.
When in doubt, it’s best to replace insulin at the first signs of any degradation or possible contamination. Using spoiled insulin is unsafe and puts your health at risk.
Does Refrigerated Insulin Lose Potency?
Yes, insulin that is expired or stored improperly can begin losing potency, making it less effective at lowering blood sugars as expected.
The proteins in insulin start naturally breaking down over time, which reduces the medication’s glucose-lowering strength and duration of action. Environmental factors like heat and light exposure accelerate insulin’s degradation process.
Using weakened, less potent insulin could lead to hyperglycemic episodes or spikes in your blood sugar levels after injecting. That’s because the insulin dose you’re taking has reduced bioavailability and activity compared to when it was in peak condition.
Sticking to insulin’s 28-31 day refrigerated shelf life helps avoid using insulin that has lost meaningful potency for managing your blood sugar levels optimally.
Tips for Traveling with Insulin
Traveling poses unique challenges for keeping insulin at controlled refrigerator temperatures. Here are some tips for travel:
– **Ask about fridge access** – Request fridge space to store insulin at your accommodations.
– **Insulin travel cases** – These keep insulin cool for trips, usually with ice packs.
– **Cooler bag** – Use a small cooler with ice or cold packs for insulin on road trips.
– **Bubble wrap insulation** – Wrap vials and pens to shield from extreme temps in luggage.
– **Carry-on luggage** – Keep insulin with you, not checked bags exposed to elements.
– **Avoid extreme heat** – Don’t leave insulin vials in hot cars for more than one hour max.
– **Temperature monitors** – Use devices to track insulin temp when in transit or storage.
– **Bring backup** – Pack extra insulin as a precaution in case vials get too warm.
With some preparation and planning, you can ensure your insulin stays within the ideal temperature range when traveling. Never use insulin that has been frozen or overheated during transit or storage.
Troubleshooting Warm Insulin
If your insulin gets too warm, here are some troubleshooting tips:
– **Identify temperature** – First step is to identify how warm it got and for how long. This impacts whether it can still be used.
– **Check for damage** – Look closely for any changes indicating heat damage like stickiness, frosting, or color shifts.
– **Contact manufacturer** – Call the insulin company’s support line whenever in doubt about usage.
– **Test blood sugar frequently** – Closely monitor BG levels upon using insulin that may have been warmed.
– **Discard if uncertain** – When unsure, or if insulin reached over 98.6°F for over 28 days, play it safe and dispose.
– **Request pharmacist guidance** – Ask your pharmacist for advice handling warm insulin based on factors like temperature and duration.
– **Use backup insulin** – Switch to backup supply if primary insulin was subject to extreme heat or temperature swings.
– **Adjust other meds** – Your doctor may advise adjusting other diabetes meds until you get replacement insulin.
– **Restock emergency kits** – Check your travel and emergency insulin to ensure you have usable backup when needed.
With caution, mild to moderately warm insulin can often still be used effectively. When in doubt, seek professional guidance and monitor blood sugar closely with any insulin subjected to heat.
Insulin Shelf Life FAQs
Some frequently asked questions about how long insulin lasts and proper storage:
**How should I store my insulin at home?**
Insulin should be stored in the refrigerator between 36-46°F. Keep in the center or back, away from the cooling element. The door is subject to temperature fluctuations.
**How long can insulin be left out unrefrigerated?**
Most insulin can remain stable at room temperature under 86°F for 28 days. Discard insulin left out any longer or exposed to over 98.6°F.
**Can you freeze insulin to extend its life?**
No, never freeze insulin. Extreme cold damages the proteins. Frozen insulin must be discarded.
**Can I use insulin past the expiration date?**
It’s not recommended. Expired insulin is more likely to have reduced potency and effectiveness. Only use past date if unopened and refrigerated.
**How do I travel with insulin?**
Pack insulin in carry-on, not checked luggage. Use insulated cases with ice packs to keep cool. Request fridge access at your accommodations.
**How often should I change my insulin pen needles?**
Change the needle after each injection. Reusing needles increases risk of contamination. Use a fresh needle tip for each use.
**How do I dispose of used insulin needles safely?**
Never toss loose sharps in the trash. Use at-home needle clippers, destruction devices, or put in a sharps container for proper disposal.
**What should I do if there are floaters or particles in the insulin?**
Insulin with visible particles should not be used. These floaters suggest contamination or chemical degradation. Replace the vial or pen immediately.
**Can I mix different types of insulin in one syringe?**
No, never mix different insulins together in the same syringe. Even similar types like various long-acting insulins should not be combined or mixed.
The Takeaway
When stored properly in the refrigerator between 36-46°F, unopened insulin typically lasts 2-3 years past its printed expiration date, and opened insulin vials or pens can last 28-31 days. Heat exposure, direct sunlight, damage, and contamination will shorten refrigerated insulin’s shelf life. Check insulin frequently for any changes in appearance like clumping or discoloration and replace immediately if it seems compromised. With proper storage and handling, insulin can remain safe and effective for monthly use in managing diabetes.