How to Store Humalog Insulin Pens & Vials

Quick answer: Yes, Humalog needs to be refrigerated before opening to stay effective. Once in use, it can stay at room temperature for up to 28 days (or 10 days for Mix75/25 KwikPens). Be sure not to expose Humalog to heat, sunlight, or freezing temperatures

Starting insulin therapy can be overwhelming, but by taking it one step at a time and working closely with your healthcare team, you can manage your diabetes and achieve better health.

Humalog is a brand name for insulin lispro, a fast-acting (mealtime) insulin used to manage blood sugar spikes after eating. It's commonly prescribed to people with both type 1 and type 2 diabetes and comes in several forms-vials, cartridges, and prefilled pens like the Humalog KwikPen.

One thing that is often overlooked about insulin is its storage conditions. Yet, it's a very important aspect of diabetes self-care, as the effectiveness of your treatment depends on it.

By educating yourself on how to store your insulin correctly at home, you can significantly improve your blood sugar levels.

Today, let's focus on Humalog, one of the most prescribed insulins in the United States.

Humalog Travel Cases and Coolers Bags - 4AllFamily USA

Want to learn more about this topic? Check out this video to dive deeper!

Does Humalog need to be refrigerated?

Yes, Humalog needs to be refrigerated before use to maintain its potency. Like all insulin types, Humalog is sensitive to temperature and light, and improper storage can affect its effectiveness.

Why does Humalog need refrigeration?

Humalog is a protein hormone, and exposure to heat, light, or freezing temperatures can cause it to break down. This leads to insulin that's less effective or completely ineffective.

Refrigeration helps preserve its stability, slows degradation, and keeps it potent longer. Poorly stored insulin can cause blood sugar spikes or inconsistent dosing.

For example, heat or direct sunlight can cause insulin to clump, clogging needles. On the flip side, freezing temps can destroy its active ingredients.

That's why it's crucial to store Humalog following the manufacturer's guidelines and take precautions when traveling or during warm seasons.

Humalog KwikPens and vials: the different forms of Humalog

Humalog is available in several convenient forms to meet different needs and lifestyles, and each form has specific storage instructions you should be aware of to keep the insulin effective and safe.

Humalog Vials - Small glass bottles of liquid insulin lispro. These are used with a syringe for injection.
Humalog Cartridges - Plastic containers that fit into reusable insulin pens. They're designed for people who prefer a pen-style injector but want to reuse the device.
Humalog KwikPen - A prefilled pen designed to be used with disposable needles containing 300 units of Humalog. It's ready to use and convenient for people on the go.
Humalog Junior KwikPen - A smaller version of the KwikPen that allows for half-unit dosing. This is especially helpful for children or people who need smaller, more precise doses.
Humalog Mix75/25 KwikPen - A prefilled pen that contains a mix of 75% insulin lispro protamine suspension (intermediate-acting) and 25% insulin lispro (rapid-acting). This mix is used to help manage blood sugar both between and after meals.

Choosing the right form of Humalog depends on your lifestyle, preferences, and medical needs. A healthcare provider can help determine which option is best for you or your loved one.

How long does Humalog last?

It's important to know how long you can use your Humalog, both before and after opening. The lifespan of Humalog depends on the type you're using and whether it's been opened or not.

✅ Unopened (refrigerated): Until expiration date.

✅ Opened vials: 28 days at room or fridge temp.

✅ Opened cartridges & pens: 28 days at room temp.

✅ Humalog Mix pens: 10 days at room temp only.

Always check the label and ask your healthcare provider if you're unsure about how long your insulin is safe to use. Using Humalog past its recommended timeframe may make it less effective in controlling blood sugar.

Humalog storage instructions

Whether you're using pens, cartridges, or vials, it's important to store Humalog correctly so it stays safe and effective.

✅ DO:

Store unopened Humalog in the refrigerator at 36°F to 46°F (2°C to 8°C).
Keep it in its original packaging to protect it from light.
Use within 28 days once opened-this includes vials, cartridges, and pens.
Check the appearance before using. Humalog should be clear and colorless. If it's cloudy, discolored, or has particles, throw it away.
Store without a needle attached to pens or cartridges to prevent air bubbles, incorrect dosing, or contamination.
Discard any pen, cartridge, or vial after 28 days, even if it still contains insulin.

❌ DON'T:

Don't freeze Humalog. Frozen insulin is no longer usable and must be discarded.
Don't expose it to heat or direct sunlight, as this can damage the insulin and reduce its effectiveness.
Don't use Humalog past the expiration date on the packaging, even if it's been stored correctly.
Don't store cartridges or pens with a needle still attached, as this can cause contamination and dosing issues.

Proper storage helps ensure that your Humalog works the way it should when you need it most.

How long can Humalog be unrefrigerated?

Once opened or in use, Humalog can be stored at room temperature (59°F to 86°F or 15°C to 30°C), but only for a limited amount of time, depending on the format:

How long is Humalog good for after opening?

Vials: Up to 28 days at room or fridge temperature.
Cartridges and KwikPens: Up to 28 days at room temperature only. These cannot be put back in the fridge once opened.
Humalog Mix Pens: Must be used within 10 days at room temperature. Do not refrigerate after opening.

💡Pro tip: Always discard any format after its time limit, even if insulin remains.

Does Humalog KwikPen need to be refrigerated?

Before Opening:

Yes. Store KwikPens in the fridge at 36°F to 46°F (2°C to 8°C).

After Opening:

Once opened, do not return to the refrigerator. Keep them at room temperature (59°F to 86°F) and use within 28 days (10 days for Humalog Mix pens).

Humalog Mix 75/25 storage instructions

⚠️ If you use Humalog Mix75/25 or Mix50/50, it's important to know that storage guidelines are a little different compared to standard Humalog insulin. These mixed insulins contain both short- and intermediate-acting components, which makes them more sensitive to temperature and handling.

Proper storage ensures the insulin works as intended, so if you're prescribed a mix, make sure you're following these specific guidelines:

Unopened Pens & Vials:

Store in the refrigerator at 36°F to 46°F (2°C to 8°C) until you're ready to use them.
Keep them in their original packaging to protect them from light.

Opened Vials:

Once opened, vials can be stored either in the fridge or at room temperature (up to 86°F or 30°C) for up to 28 days.
Avoid freezing or exposing them to heat or sunlight.

Opened Pens:

Here's where it gets especially important: opened Humalog Mix pens should only be stored at room temperature (below 86°F / 30°C).
Do not refrigerate again after the first use.
These pens should be used within 10 days and discarded after that, even if they still contain insulin.

Quick summary: forms of Humalog & their storage needs

Vials:

✅ Refrigerate unopened.

✅ After opening, store in the refrigerator or at room temperature for up to 28 days.

Cartridges (for reusable pens):

✅ Refrigerate unopened.

✅ After opening, store at room temperature only (59°F to 86°F / 15°C to 30°C) for up to 28 days.

❌ Do not refrigerate again once in use.

KwikPens (Prefilled):

✅ Refrigerate unopened.

✅ Once opened, store at room temperature for up to 28 days.

❌ Do not return to the fridge.

Junior KwikPens:

✅ Same storage rules as the standard KwikPen, refrigerate unopened

✅ Keep at room temperature for up to 28 days once in use.

Mix75/25 KwikPens:

✅ Refrigerate unopened.

✅ Once opened, store only at room temperature and discard after 10 days, even if insulin remains.

Bonus tips for safe Humalog storage

Keep track of how long your insulin has been open. Setting a reminder on your phone can help.
Always check your insulin's appearance before injecting. Clear = good. Cloudy or clumpy = time to toss.
Keep Humalog cool when you're traveling. 4AllFamily offers a wide selection of insulin travel cases and coolers for Humalog to help keep your insulin safe without a fridge.

Proper Humalog storage is critical for safe and effective diabetes treatment. Following refrigeration guidelines and understanding how long each format lasts will help you maintain stable blood sugar and avoid complications.

Key Take Aways:

When it comes to storing your Humalog, make sure you remember these key points:

💉 Keep It Cool (Until Opened): Humalog should be refrigerated until first use. After opening, it can be stored at room temperature for up to 28 days (or 10 days for Mix75/25 KwikPens).

🌡️ Avoid Extremes: Never freeze Humalog or leave it in direct sunlight or heat, as extreme temperatures can break it down and make it unsafe to use.

📆 Know Your Insulin Type: Mix75/25 and other Humalog pens may have different storage guidelines. Always double-check the label or package insert.

✈️ Plan Ahead for Travel: Use insulated bags or travel cases to keep Humalog at a safe temperature when you're on the go or in warm climates.

We'd Love to Hear From You!

💬 Have a question about storing Humalog or a tip that's worked for you? We'd love to hear from you. Share your thoughts in the comments! Whether you're a newly diagnosed patient or a seasoned pro, your insights could help someone else manage their insulin with confidence. Let's support each other!

📆 Article Update History:

✅ Updated: April 23, 2025

Originally Published: March 21, 2023

March 21, 2023

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The information presented in this article and its comment section is for informational purposes only and is not intended as a replacement for professional medical advice. Always consult with a qualified healthcare provider for any medical concerns or questions you may have.

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