Quick answer: All forms of unopened Novolog need to be refrigerated between 36-46°F (2°C to 8°C) except for the Novolog Mix 70/30 flex pens. Once opened, pens and cartridges should be kept at room temperature, while vials can be stored either way. Always avoid heat, light, and freezing.
Novolog is a fast-acting insulin (insulin aspart) used to control blood sugar levels during meals. It starts working within 5-15 minutes and peaks within 1-3 hours. It's often referred to as mealtime or bolus insulin.
Novolog is available in several forms:
- Vials (10 mL) - used with insulin syringes
- Pre-filled autoinjector pens like the Novolog FlexPen (3 mL)
- Cartridges for reusable pens like the NovoPen Echo
- Novolog Mix 70/30 - a premixed combination of insulin aspart and insulin aspart protamine for longer action
Novolog is one of the most widely prescribed insulins in the U.S., used by millions of people managing type 1 or type 2 diabetes. But did you know that most people don't know how to store it correctly?
Improper storage can make your insulin less effective, or even useless, putting your health at risk.
In this guide, we are taking the guesswork out of insulin storage and breaking down break down everything you need to know about how to store Novolog.
Does Novolog need to be refrigerated?
The short answer is yes. Like all insulins, including Lantus, Fiasp, Apidra, Toujeo, Humalog, and others, unopened Novolog must be refrigerated. Once it's opened, the rules change slightly depending on the form you're using.
Before Opening
Before you use Novolog for the first time, it should be kept in the fridge. The ideal temperature is between 36°F and 46°F (2°C to 8°C).
⚠️ Important: Don't ever freeze it. If your insulin gets frozen, even by accident, it's no longer safe to use, even if it thaws out later.
What if you don't have a fridge nearby for a bit?
That's okay, unopened Novolog can stay at room temperature (up to 86°F or 30°C) for up to 28 days. Just make sure it's not left somewhere hot or in direct sunlight.
After Opening
Once you start using a Novolog pen or vial, you no longer need to keep it in the fridge, but you do need to protect it from heat and light.
Here's what to do:
- Novolog FlexPens and cartridges: Store at room temperature only. Do not refrigerate again after opening. They're good for up to 28 days after first use.
- Novolog vials: Store either in the fridge or at room temperature after opening. They also last 28 days once in use.
Related article: Does Insulin Need to Be Refrigerated? How to Store it Correctly?
Novolog Mix 70/30: Storage Instructions
Novolog Mix 70/30 comes in two forms: vials and FlexPens-and each one has slightly different storage rules.
FlexPens:
- Before use: Don't refrigerate! Keep them at room temperature (up to 86°F or 30°C) for up to 14 days.
- After opening: You can store them at room temperature or in the fridge, but either way, use them within 14 days.
Vials:
- Before use: Keep unopened vials in the fridge (36°F to 46°F or 2°C to 8°C) until the expiration date. No fridge? No problem! They can also stay at room temperature for up to 28 days.
- After opening: Vials can be kept in the fridge or at room temperature, but must be used within 28 days.
Related article: Insulin and Heat: How to Keep Your Supplies Safe in High Temperatures!
How long can Novolog stay unrefrigerated?
If it hasn't been opened yet, Novolog can be left out of the fridge for up to 28 days, as long as the room temperature stays below 86°F (30°C).
Once opened:
✅ Pens and cartridges should always be kept at room temperature, not cold
✅ Vials can be stored at either room temperature or in the fridge
✅ Insulin should never be exposed to direct sunlight, extreme heat, or freezing conditions
If you live somewhere warm, be especially careful, as heat above 86°F can ruin insulin even if it's only for a short time.
Related article: How to Store Insulin Without Refrigeration? Practical Tips from a Type 1 Diabetic!
How long is Novolog good for after opening?
Whether you're using a pen or a vial, Novolog has a clear limit once opened: usually 28 days.
Here's a quick breakdown:
- Novolog FlexPen: good for up to 28 days at room temperature. Do not refrigerate after opening.
- Novolog vial: lasts 28 days whether stored in the fridge or at room temperature.
- Novolog Mix 70/30 FlexPen: lasts only 14 days after opening.
After those 14 or 28 days, even if you still have insulin left, it should be thrown away.
💡Helpful tip: Write the date you first use each new pen or vial directly on the label with a permanent marker. That way, you don't have to guess when it's time to toss it.
Related article: Is Your Insulin Still Safe? What Happens When It's Left Out for 1 Hour or Overnight
Novolog expiration information
Does Novolog expire?
Yes. All insulin, including Novolog, has an expiration date printed on the packaging. You should:
- Never use Novolog past its expiration date
- Always check your insulin before use
- Discard any pen or vial 28 days after opening, even if there's insulin left
Related article: Does Insulin Expire and How Long is it Good for?
Can you use Novolog after the expiration date?
No. Like all medications, insulin has an expiration date printed on the box and on each pen or vial. You should never use Novolog past that date, even if it looks fine.
Also, remember that once you open a pen or vial, it only lasts for a certain amount of time, either 14 or 28 days, depending on the type, even if it hasn't technically "expired" yet.
How to tell if Novolog has gone bad
It's always a good idea to inspect your insulin before using it. Here's how to know if your Novolog is still good, or if it's time to throw it out.
For regular Novolog (clear insulin):
- It should look totally clear and colorless, like water.
- Don't use it if it's cloudy, has particles or clumps, or looks discolored.
- If it smells unusual or your blood sugar isn't responding like usual, it might have gone bad.
For Novolog Mix 70/30 (cloudy insulin):
- It should look evenly cloudy or milky after gentle mixing.
- Don't use it if it separates or has chunks, even after rolling it between your hands.
And remember, if you're ever unsure, it's always safer to throw it away and use a fresh pen or vial.
Related article: How to Tell if Your Insulin Has Gone Bad?
Best Ways to Store Novolog While Traveling
Depending on whether your insulin is opened or unopened, you'll need different types of cooling gear.
Traveling with unopened Novolog (Refrigerated)
Use an insulin travel fridge or ice-pack cooler to keep it at 36-46°F (2-8°C).
We recommend:
✅ The Voyager Travel Fridge - holds 7 pens, powered by USB or battery, keeps insulin refrigerated for 30 hours without power.
✅ The Nomad Cooler by 4AllFamily - lightweight, fits 3-7 pens, includes gel ice packs for up to 30 hours of cooling.
For in-use pens (at Room Temperature)
These don't need refrigeration, but still need to be kept below 86°F (30°C). For hot climates:
We recommend:
✅ The Chillers Insulin Cool Pouches: Keep insulin cool for up to 45 hours without ice or electricity!
✅ The Rambler Insulin Pen Travel Case: Keeps one insulin cool for up to 16 hours!
More tips for traveling with Novolog
Traveling with Novolog takes a bit of planning, but with the right prep, you can stay safe and stress-free on your journey. Here are some expert-backed tips to make sure your insulin stays effective and accessible wherever you go:
🎒 Carry extra supplies: Always pack more than you think you'll need. Bring extra Novolog pens, vials, needles, syringes, and any other essential supplies in case of delays, lost luggage, or other unexpected issues.
📄 Bring a doctor's note or prescription: Carry a diabetes travel letter from your doctor that explains your need for insulin and lists the specific products you're carrying. This can be helpful during airport security checks or when going through customs, especially for international travel.
🌍 Check travel regulations: If you're traveling internationally, research the rules for bringing insulin into your destination country. Some countries have specific limits or may require permits or documentation in advance.
🕒 Plan for time zone changes: Crossing time zones? You may need to adjust your insulin schedule. Talk to your healthcare provider ahead of time about how to safely adjust your doses based on the time difference.
💬 Talk to a healthcare provider before your trip: Everyone's needs are different. Before you travel, consult your doctor or pharmacist for personalized guidance to ensure your insulin stays safe and your routine stays on track.
Related article: The Ultimate Checklist for Traveling with Diabetes!
Final tips for safe Novolog storage
Storing your Novolog correctly isn't just about following the rules, it's about making sure your insulin stays safe, effective, and ready to help you manage your blood sugar.
Whether you're at home, at work, or traveling, knowing how to handle both unopened and in-use Novolog pens and vials can protect your health and avoid wasted medication.
Stick to the guidelines, and when in doubt, it's always better to start fresh with a new pen or vial.
Key Take Aways:
Here are some important key takeaways to remember:
💉 Refrigerate Before Use: Unopened Novolog must be kept in the fridge (36-46°F), but it can be at room temp (up to 86°F) for 28 days.
🖊️ Room Temp After Opening: Once opened, pens and cartridges should not be refrigerated again, store at room temperature and use within 28 days (14 for Mix 70/30 FlexPen).
⚠️ Avoid Heat and Freezing: High temperatures or freezing will ruin insulin, and even once it can make it ineffective.
✈️ Travel Smart: Use insulin coolers or travel fridges for unopened Novolog, and insulated bags for in-use pens in warm climates.
We'd Love to Hear From You!
💬 Have questions about storing your Novolog? Or maybe a trick for keeping your pens cool on the go? We'd love to hear from you! Share your tips, personal experience, or questions in the comments below. Your insight could help someone else stay safe and confident with their Novolog!
📆 Article Update History:
✅ Updated: April 30, 2025
Originally Published: March 21, 2023
