Does Tirzepatide Need to Be Refrigerated? Storage Rules
Does tirzepatide need to be refrigerated? Yes: the Zepbound and Mounjaro labels say to keep it in a fridge at 2°C to 8°C (36°F to 46°F). It can spend a limited time out of the fridge, as long as it stays at or below 30°C (86°F). It must never be frozen.
Below are the storage rules from the labels for each pen and vial, plus what the FDA says about warm deliveries and compounded vials.
Short answer
- Does tirzepatide need the fridge?
- Yes. Both US labels say 2°C to 8°C (36°F to 46°F) for single-dose pens and vials.
- How long can it be out?
- A total of 21 days for single-dose pens and vials, and 30 days for Zepbound multi-dose vials and KwikPens, never above 30°C (86°F).
- Can it be frozen?
- No. The Zepbound label says do not freeze it, and do not use it if it was frozen.
- What if it arrives warm?
- The FDA recommends not using any injectable GLP-1 drug that arrives warm.
Sources: Zepbound FDA label, section 16.2 Storage and Handling; Mounjaro FDA label, section 16.2 Storage and Handling; FDA page on unapproved GLP-1 drugs
What do the tirzepatide labels say about refrigeration?
The Zepbound and Mounjaro labels say to keep tirzepatide in a fridge at 2°C to 8°C. They also say how long it may spend out of the fridge.
- Fridge: 2°C to 8°C (36°F to 46°F), for both Zepbound and Mounjaro single-dose pens and vials.
- Out of the fridge: allowed for a limited time, never above 30°C (86°F).
- Freezing: do not freeze it, and do not use it if it was frozen.
- Heat and light: the Zepbound label says to protect it from both.
Sources: Zepbound FDA label, section 16.2 Storage and Handling; Mounjaro FDA label, section 16.2 Storage and Handling
How should each tirzepatide pen and vial be stored?
It depends on the product. The Zepbound label allows 21 days out of the fridge for single-dose pens and vials, and 30 days for multi-dose vials and KwikPens.
| Product | In the fridge | Out of the fridge | Freezing, heat and light |
|---|---|---|---|
| Zepbound single-dose pen | 2°C to 8°C (36°F to 46°F) | Up to a total of 21 days, not above 30°C (86°F) | Do not freeze. Protect from heat and light |
| Zepbound single-dose vial | 2°C to 8°C (36°F to 46°F) | Up to a total of 21 days, not above 30°C (86°F) | Do not freeze. Protect from heat and light |
| Zepbound multi-dose vial, unopened | In the fridge it can be used until the expiration date | Throw away after 30 days at room temperature, up to 30°C (86°F) | Do not freeze. Protect from heat and light |
| Zepbound KwikPen, unopened | In the fridge it can be used until the expiration date | Throw away after 30 days at room temperature, up to 30°C (86°F) | Do not freeze. Protect from heat and light |
| Zepbound multi-dose vial or KwikPen, opened | Throw away 30 days after first use | Throw away after a total of 30 days at room temperature | Also throw away after 4 weekly doses, even if medicine is left |
| Mounjaro single-dose pen or vial (US) | 2°C to 8°C (36°F to 46°F) | Discard after a total of 21 days at room temperature | Not covered in our sources |
| Mounjaro pen or vial (EU) | Not covered in our sources | Up to 21 cumulative days below 30°C, then discard | Not covered in our sources |
Where a cell says not covered, the label may still have a rule. Our sources for this page did not include it.
Sources: Zepbound FDA label, section 16.2 Storage and Handling; Mounjaro FDA label, section 16.2 Storage and Handling; Mounjaro EU product information (EMA), storage
How long can tirzepatide stay out of the fridge?
The Zepbound label allows a total of 21 days out of the fridge for a single-dose pen or vial, and 30 days for a multi-dose vial or KwikPen. In both cases the room must not go above 30°C (86°F).
The word total matters. The Zepbound label says each single-dose pen or vial can be stored unrefrigerated for up to a total of 21 days, if needed. So time out of the fridge adds up, even if the pen goes back in between.
The multi-dose vial and KwikPen have their own rules. If not yet opened and kept at room temperature, the label says to throw it away after 30 days. Once opened, the label says to throw it away after a total of 30 days at room temperature, 30 days after first use, or after 4 weekly doses. That holds even if there is medicine left in it.
Sources: Zepbound FDA label, section 16.2 Storage and Handling
How do you count tirzepatide days out of the fridge?
Add up every day the pen or vial spends out, because the labels set a total, not one stretch. The two worked examples below use only the label limits.
- A Zepbound single-dose pen is out for 5 days, goes back in the fridge, then is out for 10 more days. It has used 15 of its 21 days.
- A Zepbound multi-dose vial is opened on day 1. The label says to throw it away after 30 days from first use, after a total of 30 days at room temperature, or after 4 weekly doses. Any one of these ends its use, even if medicine is left.
These examples are our own arithmetic from the label rules. They are not printed in the label.
Sources: Zepbound FDA label, section 16.2 Storage and Handling
How long can Mounjaro be at room temperature?
The US Mounjaro label says a total of 21 days, the same as Zepbound single-dose pens. Both brands contain the same medicine, tirzepatide.
The US Mounjaro label says to discard the single-dose pen or vial after a total of 21 days at room temperature. The EU product information says Mounjaro can be stored unrefrigerated for up to 21 cumulative days below 30°C. After that, the pen or vial must be discarded.
For how the two brands compare, see is Zepbound the same as Mounjaro.
Sources: Mounjaro FDA label, section 16.2 Storage and Handling; Mounjaro EU product information (EMA), storage
What happens if you forgot to refrigerate Zepbound?
The Zepbound label counts time out of the fridge as a running total, up to 21 days for a single-dose pen, at or below 30°C (86°F). So what matters is the total time out and how warm it got.
Three questions match the label rules:
- Was the room at or below 30°C (86°F)? Above that is outside the label limit.
- How much time has the pen spent out in total? For a single-dose pen, the limit is 21 days.
- Was it ever frozen? The label says not to use it if it was.
If you are not sure whether a pen is still within the label rules, a pharmacist can check it with you.
Sources: Zepbound FDA label, section 16.2 Storage and Handling
What happens if tirzepatide gets too warm?
The labels do not explain what heat does inside the pen; they only set the limits. The Zepbound label says never above 30°C (86°F) out of the fridge, and to protect it from heat.
The FDA says injectable GLP-1 drugs need refrigeration as stated in their package inserts. It recommends patients not use any injectable GLP-1 drug that arrives warm or without enough cooling, as this can affect the drug's quality.
Sources: Zepbound FDA label, section 16.2 Storage and Handling; FDA page on unapproved GLP-1 drugs
Can tirzepatide be frozen?
No. The Zepbound label says do not freeze it, and do not use it if it has been frozen. The fridge range on the label, 2°C to 8°C, sits above freezing.
Sources: Zepbound FDA label, section 16.2 Storage and Handling
Does tirzepatide need to be kept away from light?
Yes. The Zepbound label says to protect it from heat and light, in the same line that says not to freeze it.
Sources: Zepbound FDA label, section 16.2 Storage and Handling
Does tirzepatide expire?
Yes. The Zepbound label says an unopened multi-dose vial or KwikPen kept in the fridge lasts until the printed expiration date.
Once it is out of the fridge or opened, the shorter limits in the table above apply as well. The printed date and those time limits both count.
Sources: Zepbound FDA label, section 16.2 Storage and Handling
How do you store tirzepatide when travelling or in hot weather?
The labels give no separate travel rule, so the same limits apply. The key number is 30°C (86°F), the Zepbound label limit for time out of the fridge.
The label rules that matter on a trip
- Out of the fridge, it must stay at or below 30°C (86°F).
- Days out add up: a total of 21 for single-dose pens and vials, 30 for multi-dose vials and KwikPens.
- It must not freeze, and a frozen pen should not be used.
- It should be kept away from heat and light.
A room, a car or a bag that is warmer than 30°C (86°F) is outside the label rules. Our guide to storing peptides in Vietnam heat looks at keeping injectables cool in a hot climate.
Sources: Zepbound FDA label, section 16.2 Storage and Handling
What should you do if tirzepatide arrives warm?
The FDA recommends that patients not use any injectable GLP-1 drug that arrives warm or without enough cooling. It says this can affect the drug's quality.
The FDA also says injectable GLP-1 drugs need refrigeration as stated in their package inserts. That covers tirzepatide, which is an injectable GLP-1 type drug.
Sources: FDA page on unapproved GLP-1 drugs
How should compounded tirzepatide be stored?
No official source gives a storage rule for compounded tirzepatide. The label rules above are for the brand products only.
The FDA says compounded drugs are not FDA approved. It does not review them for safety, effectiveness or quality before they are sold. The FDA also says that, in general, vials with several doses of a sterile medicine should be used within 28 days after first use, because the risk of contamination is higher after that.
A 2026 review in the Annals of Pharmacotherapy found that only 18% of the compounded products it looked at gave a beyond use date and preferred storage conditions.
Sources: FDA page on unapproved GLP-1 drugs; Ann Pharmacother 2026 review of compounded GLP-1 products
Other tirzepatide questions people ask with storage
People who search for tirzepatide storage also ask the questions below. Each answer comes from the labels.
What is the mechanism of action of tirzepatide?
The Zepbound label says tirzepatide binds to and switches on two hormone receptors, called GIP and GLP-1. It is the medicine in both Zepbound and Mounjaro.
What are the benefits of tirzepatide besides weight loss?
The labels list two other approved uses. The Zepbound label lists treating moderate to severe obstructive sleep apnea in adults with obesity. The Mounjaro label lists improving blood sugar control, along with diet and exercise, in adults and children 10 and older with type 2 diabetes.
How long does tirzepatide take to kick in?
The Zepbound label says blood levels peak at a median of 24 hours after a shot, with a range of 8 to 72 hours. Our sources for this page do not cover how soon weight changes.
What should you avoid while taking tirzepatide?
For storage, the Zepbound label says to avoid freezing, heat and light. Our sources for this page do not cover other things to avoid; the tirzepatide dosage guide covers what the label says about other medicines.
Sources: Zepbound FDA label, sections 1, 12.1 and 12.3; Mounjaro FDA label, section 1 Indications and Usage
What do the labels not say about tirzepatide storage?
Three storage questions have no answer in the labels or FDA pages we used.
What heat does to the medicine
The labels give a 30°C (86°F) limit, not a reason for it.
A storage rule for compounded vials
No maker data for compounded tirzepatide appears in the sources we used.
Whether a pen left out too long is still safe
The labels only give the limits. A pharmacist can check a pen against them.
Sources: Zepbound FDA label, section 16.2 Storage and Handling; FDA page on unapproved GLP-1 drugs
Tirzepatide refrigeration questions
Does tirzepatide have to be refrigerated?+
Yes. The Zepbound and Mounjaro labels both say to store single-dose pens and vials in a refrigerator at 2°C to 8°C (36°F to 46°F). The labels also allow limited time out of the fridge, with set limits.
How long can my tirzepatide stay out?+
For the Zepbound single-dose pen or vial, the label says it can be stored unrefrigerated, not above 30°C (86°F), for up to a total of 21 days. For an unopened multi-dose vial or KwikPen, the label says to throw it away after 30 days at room temperature.
How long can Mounjaro be at room temperature?+
The US Mounjaro label says to discard the single-dose pen or vial after a total of 21 days at room temperature. The EU product information says Mounjaro can be stored unrefrigerated for up to 21 cumulative days below 30°C, and then the pen or vial must be discarded.
What happens if you forgot to refrigerate Zepbound?+
The label counts time out of the fridge as a running total. A single-dose pen or vial can be out for up to a total of 21 days, not above 30°C (86°F). If you are unsure whether a pen is still usable, a pharmacist can check it against the label.
Can tirzepatide be frozen?+
No. The Zepbound label says do not freeze it, and do not use it if it has been frozen. It also says to protect it from heat and light.
Does tirzepatide expire?+
Yes. The Zepbound label says an unopened multi-dose vial or KwikPen can be used until the expiration date on the label if it is kept in the fridge. Once out of the fridge or opened, the shorter limits on this page apply.
What if my tirzepatide arrives warm?+
The FDA says injectable GLP-1 drugs need refrigeration as stated in their package inserts. It recommends patients not use any injectable GLP-1 drug that arrives warm or without enough cooling, because this can affect the drug quality.
Can tirzepatide go back in the fridge after being out?+
The labels count time out as a total, not one stretch: the US label says up to a total of 21 days, and the EU text says 21 cumulative days. Every day out counts toward that total.
Sources: Zepbound FDA label, section 16.2 Storage and Handling; Mounjaro FDA label, section 16.2 Storage and Handling; Mounjaro EU product information (EMA), storage; FDA page on unapproved GLP-1 drugs
Related tirzepatide guides
This guide is for educational purposes only and is not medical advice. It describes what the FDA labels, the EU product information and FDA guidance say about storing tirzepatide. Questions about a specific pen or vial belong with a pharmacist or a licensed clinician.