Does Mounjaro Need to Be Refrigerated? Tips for Proper Mounjaro Storage at Home

Quick answer: Mounjaro does need to be refrigerated between 36°F and 46°F (2°C and 8°C) to stay effective. Mounjaro can be out of the fridge for up to 21 days at room temperature (below 86°F/30°C). After that, it should be thrown away, even if it hasn't expired.

Mounjaro is the latest diabetes drug to be FDA-approved in May 2022 for the treatment of type 2 diabetes. Used along with physical exercise and diet, the medicine significantly helps lower blood glucose levels, aids weight loss, and reduces the risks of diabetes-related health complications.

If you're among the numerous patients who have recently started the new Mounjaro therapy, your doctor has probably warned you about its specific storage instructions. Like many other diabetes injections, Mounjaro is a biologic drug, meaning it's sensitive to heat and must be kept refrigerated.

Let's take a closer look at this groundbreaking medication and ensure you know how to store your Mounjaro pens properly. Your treatment success depends on it!

Related article: Mounjaro Pen Malfunction: How to Fix a Defective Mounjaro Pen? Can You Get a Replacement?

Are you more of a visual learner? Check out this video on the best way to store Mounjaro!

Mounjaro is taken once weekly via subcutaneous injection with an easy-to-use single-dose autoinjector pen.

The active ingredient in Mounjaro is Tirzepatide, a GIP/GLP-1 receptor agonist drug that stimulates two hormones that control insulin production: GIP and GLP-1.

In simple terms, Mounjaro boosts insulin secretion and reduces glucagon production, helping manage blood sugar levels and reduce diabetes-related complications like heart disease, kidney disease, vision loss, and neuropathy.

Unlike other GLP-1 receptor agonist drugs like Ozempic, Byetta, Victoza, or Trulicity, Mounjaro works on both GIP and GLP-1 receptors, offering a more comprehensive therapeutic effect.

It can be prescribed on its own (always alongside exercise and diet) or in combination with other diabetes medications like metformin.

Does Mounjaro need to be refrigerated?

Yes, it does. According to Eli Lilly, the manufacturer of Mounjaro, this medication must be refrigerated to preserve its potency.

If you've recently been prescribed Mounjaro, you may already know that it requires specific storage conditions to stay effective. The active ingredient, Tirzepatide, is sensitive to both temperature and light, and it has a limited shelf life.

If not stored properly, it can break down and lose its potency, making your treatment less effective.

Let's take a closer look at how to store Mounjaro correctly so you can keep your medication safe and working as it should.

Related article: How to Inject Mounjaro and Use the Injector Pen Correctly?

How long does Mounjaro last in the fridge?

Unopened Mounjaro pens can last until the expiration date printed on the label, which is typically about one year from the date of purchase.

To ensure maximum effectiveness, store the pen in its original packaging in the refrigerator between 36°F and 46°F (2°C and 8°C).

Be careful not to place it near the freezer compartment or in direct contact with cold surfaces to avoid freezing. Regularly check your refrigerator's temperature, especially if it's shared or older, as slight changes can impact the stability of your medication.

How long can Mounjaro be out of the fridge?

Mounjaro pens can be left out of the fridge for up to 21 days, as long as the temperature stays below 86°F (30°C).

This flexibility is especially helpful if you're traveling, commuting, or need to carry your Mounjaro pen in a bag for convenience.

If you're heading to a warmer climate, consider using a travel cooler or insulated case to keep the medication protected. Just remember to avoid exposing the pen to direct sunlight or heat sources like cars, pockets, or warm bags. Proper care on the go ensures your medication stays safe and effective.

After 21 days at room temperature, even if it still looks fine and hasn't passed the expiration date, the pen should be discarded, as the medication may no longer be safe or effective.

Related article: Essential Guide to Traveling with Mounjaro: Safe Transport, Storage Tips & Best Travel Cases

Can I refrigerate Mounjaro after room temperature?

Once a Mounjaro pen has been taken out of the refrigerator and allowed to reach room temperature, it should not be placed back into the fridge. Re-refrigeration can cause condensation or affect the chemical stability of the medication.

If the pen has been stored at room temperature for fewer than 21 days and hasn't exceeded 86°F (30°C), it's still considered safe to use, but it must now stay at room temperature until it's used or thrown away.

💡Pro tip: To keep track, consider writing the "room temp start date" on the pen or box.

Related article: Does Mounjaro Need to be at Room Temperature Before Injecting? Or Can You Inject It Cold?

What happens if Mounjaro is not refrigerated?

Tirzepatide, the active ingredient in Mounjaro, is a biologic, a complex, temperature-sensitive drug created using living cells. It begins to degrade when exposed to excessive heat or light, eventually losing its effectiveness.

While expired or heat-exposed Mounjaro won't poison you, using it may seriously impair your treatment, leading to poor blood sugar control.

Always:

• Write down the date you removed the pen from the fridge.
• Discard the pen after 21 days of room temperature storage.
• When in doubt, throw it out.

Related article: Accidentally Left Mounjaro Out of the Fridge? Here’s What to Do to Keep It Safe and Effective

How to tell if Mounjaro has gone bad

Inspect the pen before each use. Mounjaro should be:

✔️ Clear or slightly yellow

✔️ Free from particles or cloudiness

If the liquid looks cloudy or contains particles, it may be spoiled. Discard the pen or return it to the pharmacy.

💡Note: Small air bubbles are normal and not a cause for concern.

What to do with expired Mounjaro pens

Because Mounjaro pens are sharps, do not throw them in the trash. Dispose of them in an FDA-cleared sharps container. If you don't have one, a heavy-duty plastic bottle (like a detergent container) will do. You can also request a free sharps container for your Mounjaro pens here.

Related article: Can You Take Mounjaro a Day Early or Change the Day of the Week for Your Injections?

Tips for how to store Mounjaro

Storing Mounjaro correctly is essential to make sure it stays safe and effective. Since Tirzepatide is sensitive to temperature and light, even small mistakes can impact the quality of your medication.

Here are some simple tips to help you store Mounjaro the right way:

✅ Keep it refrigerated: Store Mounjaro in the refrigerator at 36°F to 46°F (2°C to 8°C). Don't freeze it, as freezing can damage the medicine.

✅ Avoid heat and sunlight: Keep the pen in its original packaging until you're ready to use it. This helps protect it from light. Never leave it in a hot car, near windows, or close to heating appliances.

✅ Room temperature is okay… temporarily: If needed, Mounjaro can be kept at room temperature (up to 86°F or 30°C) for up to 21 days. After that, it should be discarded.

✅ Don't use expired pens: Always check the expiration date printed on the pen or box. Expired Mounjaro may not work as intended.

✅ Travel smart: When flying or traveling, carry Mounjaro in a medical travel cooler. Keep it in your carry-on, not in checked luggage, where temperatures can fluctuate wildly.

✅ Use a medication reminder: Whether you're at home or away, setting a weekly alarm or using a medication app can help ensure you never miss a dose.

By following these storage tips, you can help preserve the effectiveness of Mounjaro and stay on track with your treatment plan.

Related article: When to Take Mounjaro: Should You Take it in The Morning or at Night?

Why proper Mounjaro storage matters

Proper storage of Mounjaro isn't just a guideline, it's a critical part of making sure your medication works as intended.

Whether you're new to the treatment or have been using it for a while, following the correct storage practices helps protect the drug's potency and ensures your diabetes management stays on track.

With a little planning and the right tools, keeping Mounjaro safe can be simple and stress-free. When in doubt, always refer to the packaging instructions or consult your pharmacist.

Key Take Aways: 

🧊 Keep it Cool: Yes, unopened Mounjaro needs to be refrigerated between 36°F and 46°F to remain effective until its expiration date labeled on the package.

⏳ 21-Day Room Temp Rule: You can leave Mounjaro out of the fridge for up to 21 days if it stays under 86°F (30°C).

❌ No Re-Refrigerating: Once it's at room temperature, don't put it back in the fridge-use it or toss it after 21 days.

🛫 Travel Smart: Use insulated cases and avoid heat to keep your Mounjaro safe on the move.

We'd Love to Hear From You!

💬 Do you have some Mounjaro storage tips that work for you, or questions about keeping your medication safe? We'd love to hear from you! Share your thoughts and questions in the comments section below! Your experience could help others navigate the same journey.

📆 Article Update History:

✅ Updated: May 1, 2025

Originally Published: March 7, 2023