GLP-1 Storage Guide: Refrigeration, Room Temperature, Travel, and Expiration for Wegovy, Ozempic, Zepbound, and Mounjaro

GLP-1 storage rules are not common knowledge and the FDA labels are buried inside multi-page prescribing information PDFs. Patients consistently search for “does semaglutide need to be refrigerated,” “how long does tirzepatide last in the fridge,” and “does semaglutide expire” — and the answers are different for each drug, different for unopened vs in-use pens, and different again for compounded vials. This reference walks through the actual approved storage rules for Wegovy, Ozempic, Zepbound, and Mounjaro pens, the typical compounding-pharmacy beyond-use-date assignments, what to do if your medication was accidentally frozen or left at room temperature too long, and how to fly with a GLP-1.

Quick reference: storage rules at a glance

Sourced directly from the “How Supplied / Storage and Handling” section of each FDA-approved prescribing information document [1, 2, 3, 4]:

Three things stand out from the table: (1) all four drugs are normally refrigerated until first use, (2) the room-temperature window after first use varies meaningfully — Ozempic gets a much longer 56-day window than Wegovy's 28 days even though they're the same active ingredient, and (3) none of the four can be frozen. If your medication was accidentally frozen at any point, the FDA labels say to discard it, even if it has thawed and looks normal [1, 2, 3, 4].

Why Wegovy is 28 days but Ozempic is 56 days

Both Wegovy and Ozempic contain semaglutide, manufactured by the same company, in the same multi-dose pre-filled pen format. Why does Ozempic get a longer room-temperature window? The short answer is that the room-temperature stability data package the manufacturer submitted to the FDA differs between the two drugs because the doses and the in-use scenarios are different. The Ozempic pen delivers up to several months of diabetes therapy from a single pen; the Wegovy pen is a single-use higher-dose injector. The 56-day Ozempic window reflects the actual stability data Novo Nordisk generated for that specific dose-and-pen combination [1, 2]. From a patient perspective, follow whichever number applies to your specific drug, not the other one.

Compounded GLP-1 vials: different rules

Compounded semaglutide and tirzepatide vials follow different storage rules than the brand-name pens because they are prepared as patient-specific compounded preparations under USP General Chapter <797> rather than as FDA-approved manufactured products [5]. The compounding pharmacy assigns a beyond-use date (BUD) when the vial leaves the pharmacy, and that BUD is what you should rely on — not the FDA pen labels above.

Typical compounded GLP-1 BUD assignments:

• Refrigerated (2-8°C): 28-90 days from the compounding date, depending on the pharmacy's stability documentation and the specific concentration. Many 503A pharmacies assign 90 days for compounded semaglutide at 2.5 mg/mL refrigerated.
• Room temperature (15-25°C): typically not recommended for compounded preparations beyond a few days unless the pharmacy has documented stability at room temp for the specific formulation. Always refrigerate compounded vials between doses.
• Freezing: as with brand-name, do not freeze. Freezing destabilizes the peptide.

The single source of truth for your compounded vial is the BUD label printed by the compounding pharmacy. If your pharmacy didn't include a BUD on the vial, call them and ask — under USP <797> the pharmacy is required to document and assign one [5].

What to do if your medication was left out too long

Three common scenarios and the FDA-approved answer for each:

1. The pen sat at room temperature longer than the allowed window. If you have a Wegovy pen that was out of the fridge for more than 28 days (Wegovy/Zepbound/ Mounjaro) or more than 56 days (Ozempic), the FDA-approved answer is to discard the pen even if it looks normal [1, 2, 3, 4]. The peptide degrades over time at room temperature in a way that may not be visible.
2. The pen sat in a hot car (above 30°C / 86°F). The room-temperature limits in the table apply only at or below 30°C. Brief exposure to higher temperatures (a hot car for 30-60 minutes) is not directly addressed in the labels but is generally believed to be tolerable; sustained exposure (multiple hours, repeated days) is not. Conservative call: discard and replace.
3. The pen was accidentally frozen. Discard. Even if the pen has thawed and the contents look clear, the FDA labels are unambiguous on this point — frozen GLP-1 should not be used [1, 2, 3, 4].

How to fly with a GLP-1

TSA explicitly allows refrigerated injectable medications and the necessary cooling supplies through airport security in carry-on baggage [6]. Specific rules:

• Carry-on, not checked baggage. Checked baggage holds can reach freezing temperatures at altitude, which would destroy a GLP-1. Always carry the medication on with you.
• Insulated travel case + ice pack. A standard insulin/diabetic travel case with a refreezable ice pack works for trips up to about 8-12 hours. Do not let the ice pack directly contact the pen — wrap it in a cloth or use a case that has an insulated divider to prevent freezing.
• TSA notification. You don't need a prescription to bring injectables through security, but carrying the original pharmacy label or your doctor's note avoids questions. Declare the medication to the TSA officer at the start of screening if asked.
• At the destination. Refrigerate immediately on arrival. Hotel mini-fridges work; if the fridge has only a freezer compartment, use the back of the main fridge, not the freezer.

Does semaglutide expire?

Yes. The expiration date printed on the carton (for unopened pens) reflects the manufacturer's tested stability under refrigerated storage. After that date, the FDA labels say not to use the drug [1, 2]. For compounded vials, the BUD set by the pharmacy serves the same purpose [5]. Do not extrapolate past the printed date — peptide degradation is real and the manufacturer's date is the most rigorously tested boundary you have.

Common storage mistakes that ruin medication

1. Storing in the freezer compartment. The most common mistake. Refrigerator door bins or the coldest part of the main fridge are correct; the freezer is not.
2. Storing on top of the fridge or in a sunny window. Both can exceed the 30°C room-temperature limit, especially in summer.
3. Using a pen past its room-temperature window because it “still works.” Patients often rely on the absence of visible cloudiness or discoloration as a stability check. Peptide degradation can occur without visible signs. Trust the FDA-tested window, not the appearance.
4. Mixing brand and compounded vial rules. The 28-day Wegovy room-temperature window does NOT apply to a compounded vial. Compounded vials follow the BUD set by the compounding pharmacy.

Related research and tools

For the injection technique that goes with proper storage, see our injection technique guide. For the compounded vial dose math (units to mg), see our GLP-1 unit converter. For an explanation of the FDA-approved expiration windows for the brand pens, see the prescribing information PDFs cited below — every drug's “Section 16” contains the storage rules verbatim. For the difference between the brand-name pen and the compounded vial format in operational practice, see our Wegovy pen vs compounded vial deep-dive. For the regulatory framework that governs compounded BUD assignment, see our PCAB accreditation investigation.