Does tirzepatide need to be refrigerated?

Tirzepatide, the active ingredient in Zepbound and Mounjaro, is a once-weekly injection prescribed to help manage type 2 diabetes, sleep apnea, or support weight loss. If you're new to the medication or traveling with it, you might be wondering: Does tirzepatide need to be refrigerated?

Short answer: Yes, tirzepatide should be stored in the refrigerator until it’s time to use it. This is especially important if you get your prescription filled as a 90-day supply. But there are exceptions and best practices to know about. Below, we walk through proper tirzepatide storage, what could happen if it gets too warm or sits out, and how to travel with tirzepatide medications like Mounjaro or Zepbound.

All forms of tirzepatide — including Mounjaro and Zepbound — should be stored in the refrigerator. Tirzepatide and other injectable GLP-1 medications are temperature-sensitive, peptide-based drugs, so refrigeration is key to maintaining lasting stability. But if you leave it out at room temperature of up to 86°F (30°C), don’t panic. The medication stays good at room temperature for up to 21 days. 

According to the manufacturer, Eli Lilly, the ideal temperature for tirzepatide storage is 36°F–46°F (2°C– 8°C). The storage recommendations are the same for both Zepbound and Mounjaro. It’s also the same regardless of the form: the single-dose pen or single-dose vial of Zepbound or Mounjaro.  

Here are a few key guidelines for storing the Food and Drug Administration (FDA)-approved, brand-name versions of tirzepatide, Mounjaro and Zepbound, according to the prescribing information for each product:

• Store unopened Mounjaro and Zepbound in a refrigerator at 36°F–46°F.

• If needed, you can store unopened Mounjaro and Zepbound out of the refrigerator at temperatures up to 86°F for up to 21 days.

• If you store Mounjaro or Zepbound at room temperature, it should be used within 21 days or discarded. Don’t return the medication to the refrigerator.

• Don’t put Mounjaro or Zepbound in the freezer or use either drug after it’s been frozen. Avoid exposing tirzepatide to freezing temperatures, as this can damage the medication.

• Keep Mounjaro and Zepbound in the original packaging to limit exposure to light, which can affect their stability.

Mounjaro and Zepbound are single-use tirzepatide products. Each prefilled pen contains one dose, and each single-use vial contains one dose. So, after you use the medication one time, you’ll want to dispose of it right away in a sharps container. There’s no need to return it to the fridge or anywhere else for storage. 

Note that the storage and disposal guidelines may be different for compounded tirzepatide. While compounded tirzepatide is typically stored in the refrigerator, it's best to follow the pharmacy’s instructions. Check the product label or information from your pharmacy for details about storage and how long the medication stays good in or out of the fridge.

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Tirzepatide lasts until the expiration date printed on the pen or vial, as long as it stays refrigerated. This holds true for both Zepbound and Mounjaro. Once removed from the fridge, though, the clock starts ticking. 

Before each dose of tirzepatide, make it a habit to check the expiration date and take a look at the medication. It should be clear and colorless or slightly yellow. If it’s expired, cloudy, discolored, or has anything floating in it, don’t use it. Instead, dispose of it safely and contact your pharmacy or prescriber for a refill or new prescription.  

If you keep tirzepatide out of the refrigerator, it can sit at room temperature (below 86°F) for up to 21 days. This applies to both Zepbound and Mounjaro, whether you’re using prefilled pens or single-dose vials. 

But here’s the catch: Once the medication is at room temperature, it should not be returned to the refrigerator. And if you don’t use it within 21 days, it should be discarded, per the prescribing information for Zepbound and Mounjaro.

If you fill your tirzepatide prescription for a longer timeframe, such as a 90-day supply, you’ll want to put all of the cartons of Zepbound or Mounjaro in the fridge as soon as you receive them. Accidentally leaving them out could shorten their shelf life — or worse, make them unusable. That’s because tirzepatide only stays good for three weeks at room temp. To avoid wasting doses, stash your supply in the fridge and only take out one dose (i.e. one prefilled pen or single-dose vial) at a time when you're ready to use it.

Planning to travel? You can take Zepbound or Mounjaro with you unrefrigerated for up to three weeks, as long as it’s kept below 86°F and out of direct sunlight.

What happens if tirzepatide is not refrigerated?

If tirzepatide is left out for too long or stored above 86°F, the active ingredients may start to degrade. That means the medication may not work as intended.

If you’re unsure how long your medication has been out or whether it got too warm, err on the side of caution: Don’t inject it. Instead, talk to your healthcare provider or pharmacist about next steps.

Yes, tirzepatide expires. Using medication after the printed expiration date can be risky. The expiration date is the manufacturer’s guarantee that the medication will stay stable and effective if it’s been stored correctly, meaning refrigerated between 36°F and 46°F, away from light, never frozen, and sealed in the original packaging. This applies to both Zepbound and Mounjaro, whether in prefilled pens or single-dose vials.

If you’re using a compounded version of tirzepatide, the label may list a beyond-use date (BUD) instead of an expiration date. This BUD is set by the compounding pharmacy and may be much shorter — often just a few weeks or months — so always check the packaging or ask your pharmacist if you’re unsure.

What happens if you use expired tirzepatide?

It isn’t known exactly what happens if you use expired tirzepatide since it hasn’t been studied. Using expired medication isn't recommended. Over time, tirzepatide may lose its potency, and you might not get the full therapeutic effect. 

Using expired tirzepatide might not seem like a big deal, but it’s probably not worth the risk. The active ingredient can break down over time, which can lead to a loss of effectiveness for weight loss or blood sugar control. Expired or temperature-damaged injectable medications may also result in unexpected side effects, such as irritation at the injection site.

During the drug development process, pharmaceutical manufacturers perform extensive stability testing to determine the expiration date of a medication. These tests look at how temperature, humidity, and time affect a drug’s potency and safety. But these tests don’t go on indefinitely. So, even when stored properly, its effects are unknown beyond the expiration date. That’s why it’s best to stick with in-date medication and store tirzepatide properly to maximize its benefits. 

If you ever notice that your medication looks cloudy, discolored, or has particles floating in it, don’t use it, even if it hasn’t expired yet. And if your dose has expired or has been stored incorrectly, safely dispose of it and contact your pharmacy or prescriber for a replacement.

Traveling with tirzepatide is doable. You just need to plan ahead and use the following travel tips:

• Prepare ahead. Coordinate with your prescriber to get tirzepatide, especially if you need extra doses to cover the length of your trip. Having everything organized and clearly labeled helps you prepare for screening at airport security or customs. 

• Organize documentation. Storing tirzepatide in its original packaging helps protect the medication from light. Be sure to declare the medication and any other medication-related supplies, such as syringes or needles, at airport security. A note from the prescribing healthcare provider is also recommended if you’re traveling abroad with injectable meds. 

• Stow in your carry-on. If you’re flying, it’s smart to keep your medication with you in your carry-on bag. Checked luggage can get lost or delayed, and cargo holds can reach extreme temperatures. As mentioned above, tirzepatide stays good out of the fridge (up to 86°F) for up to three weeks, so you don’t have to keep it cold unless you’re traveling for longer than that. 

• Avoid freezing. If you’re trying to keep tirzepatide cold, use an insulated travel bag with gel packs to maintain the right temperature. Avoid putting the medication on ice or directly against the ice pack, which can freeze the medication.

• Avoid heat. Don’t leave tirzepatide in a hot car or direct sunlight, even briefly. Extreme heat can damage the medication.

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Whether you’re using Zepbound, Mounjaro, or a compounded version, proper storage and handling of tirzepatide is important for getting the most out of your medication. Here’s what to remember:

• Refrigeration keeps tirzepatide longer. Store your Zepbound or Mounjaro in the fridge at 36°F–46°F until you’re ready to use it or until the printed expiration date — whichever comes first.

• Storing at room temperature is okay for up to 21 days. You can keep tirzepatide out of the fridge at room temperature, up to 86°F, for three weeks. Once it's been left out at room temperature, don’t return it to the fridge; just use it within 21 days or safely discard it.

• Remember to check the expiration date. Only use the medication if it’s within its labeled expiration window. Expired medication may lose potency or degrade over time.

• Travel smart. Bring an insulated bag, if needed, and keep the medication with you in its original carton, preferably in a carry-on bag. This protects your medication from light and extreme temperatures.