Winter Shipping and Frozen Compounded GLP-1s: When Not to Use It
If your compounded semaglutide or tirzepatide froze in transit, or you can't rule it out, set it aside and call the pharmacy before using it. The FDA-approved versions of both drugs carry the same instruction: do not freeze, and do not use if frozen. Compounded versions have no FDA-reviewed storage data at all, so the pharmacy's own labeled conditions and its replacement policy are what you have to go on.
Key takeaways
- The Ozempic (semaglutide) and Mounjaro (tirzepatide) labels both say not to freeze the drug and not to use it if it has been frozen.
- Those labels set refrigerated storage at 2°C to 8°C (36°F to 46°F). Water-based injections can freeze below that range, and a box left on a porch in winter can get there.
- Compounded GLP-1s are not FDA-approved. Your pharmacy's label and instructions apply, so ask it what it allows before you use a product that may have frozen.
- Thanksgiving (November 26, 2026), Christmas (Friday, December 25) and New Year's Day (Friday, January 1, 2027) are federal holidays. Check your carrier's holiday schedule and plan refills around them.
What the approved labels say about freezing
No FDA-approved label covers compounded GLP-1s, because compounded drugs are not FDA-approved (FDA). The approved products made from the same active ingredients are the closest reference point, and their storage sections are consistent on freezing.
The Ozempic label says: "Do not freeze OZEMPIC® and do not use OZEMPIC® if it has been frozen." It also says not to store pens "in the freezer or directly adjacent to the refrigerator cooling element" (Ozempic prescribing information).
The Mounjaro label for tirzepatide says: "Do not freeze MOUNJARO. Do not use MOUNJARO if frozen." It also says to protect the drug from heat and light (Mounjaro prescribing information).
| Approved product | Refrigerated storage | Allowed outside the fridge | Freezing |
|---|---|---|---|
| Ozempic pen (semaglutide) | 2°C to 8°C (36°F to 46°F) before first use | 56 days at 15°C to 30°C (59°F to 86°F) after first use | Do not freeze; do not use if frozen |
| Mounjaro single-dose pen or vial (tirzepatide) | 2°C to 8°C (36°F to 46°F) | Up to 21 days total, not above 30°C (86°F) | Do not freeze; do not use if frozen |
| Compounded semaglutide or tirzepatide | No FDA-approved storage conditions. Follow the dispensing pharmacy's label and ask it directly. | ||
Sources: Ozempic and Mounjaro prescribing information, section 16 (Storage and Handling), as posted October 2026.
Why that logic matters for compounded solutions
Semaglutide and tirzepatide are peptides dissolved in water-based solutions. The manufacturers that studied their own formulations concluded that frozen product should not be used, and they did not make an exception for product that looks normal after thawing. A compounded formulation may use different buffers, preservatives, or concentrations. Nobody outside the pharmacy can say whether it behaves better or worse, and the pharmacy's stability data is not reviewed by FDA.
That is why the conservative default is the same: treat a frozen or possibly frozen vial as unusable until the pharmacy tells you otherwise in writing. Appearance after thawing is not proof either way. Still, the approved labels say to use the solution only if it is clear and free of particles. Wegovy specifies "clear, colorless," and Zepbound specifies "clear and colorless to slightly yellow" (Wegovy prescribing information; Zepbound prescribing information).
Premixed solution vs. lyophilized powder
Some pharmacies ship a ready-to-use solution. Others ship a freeze-dried (lyophilized) powder that you mix with a diluent such as bacteriostatic water. These are different products with different storage instructions, and only the dispensing pharmacy can tell you how cold exposure affects its version.
- Premixed solution: This is the closer match to the approved labels' "do not freeze" instruction, since it is already a liquid.
- Lyophilized powder: The powder and the diluent may have separate storage limits, and the mixed solution has its own. Ask about each one. Don't assume that "powder" means "freeze-proof."
Five checks when a winter box arrives
- Bring it in and open it right away. Don't put the box in the fridge unopened. You need to see the contents first.
- Look for ice. Check for ice crystals, slush, a solid or partly solid vial, or a cracked vial. Also check whether the cold packs are frozen solid against the vial without any insulation between them.
- Read any temperature indicator. Some shipments include a freeze or temperature indicator. If one is included, photograph it before you touch anything else.
- Document everything. Photograph the box, the packing, the vial label with lot number and beyond-use date, and the carrier's delivery scan time. Note the outdoor temperature where you live that day, if you know it.
- Quarantine and call. Put the vial in the fridge in a bag marked "do not use," then contact the pharmacy. Don't throw it out until the pharmacy says whether it needs the vial back.
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Decision table: use, hold, or replace
| What you see | What the approved labels imply | Reasonable next step |
|---|---|---|
| Vial is cold, fully liquid, clear, no ice; cold packs partly thawed | No sign of freezing | Refrigerate and follow the pharmacy's instructions. Still inspect before each dose. |
| Ice crystals or slush in the vial | "Do not use if frozen" | Don't use it. Quarantine, photograph, and request a replacement. |
| Vial now liquid, but it sat on a porch overnight in below-freezing weather | Freezing can't be ruled out | Hold it and ask the pharmacy in writing before using it. |
| Cloudy, discolored, or has particles after thawing | Labels say to use only clear solution without particles | Don't use it. Report to the pharmacy, and consider a MedWatch report. |
| Cracked vial or broken seal | Sterility can't be assured | Don't use it. Handle the glass carefully and request a replacement. |
Based on Ozempic, Mounjaro, Wegovy, and Zepbound prescribing information. These are general cautions, not product-specific rulings.
A worked example (hypothetical)
This is an illustration, not a real case. A reader's tracking shows delivery at 4:10 p.m. on a December Tuesday, and the reader gets home at 9 p.m. Overnight temperatures are forecast below freezing. The vial is liquid and clear, but the gel packs are rock-hard and pressed directly against it.
The reader can't prove the vial froze, and can't prove it didn't. Following the checks above, the reader photographs the packing and label, refrigerates the vial in a marked bag, and emails the pharmacy with the photos and delivery time. The question is simple: given this packing and exposure, does the pharmacy authorize use, and if not, will it replace the vial? A written answer protects the reader either way.
Plan refills around holiday carrier closures
Three federal holidays fall in the coming refill window: Thanksgiving on Thursday, November 26, 2026; Christmas on Friday, December 25, 2026; and New Year's Day on Friday, January 1, 2027 (OPM federal holidays). Each carrier publishes its own holiday schedule, and service can differ by delivery level, so confirm pickup and delivery days with the carrier and service your pharmacy uses.
Christmas and New Year's Day both fall on Fridays this year, so if your shipment's service doesn't deliver on weekends, a package delayed by a day can sit until Monday. Packed cold chain is designed for a limited window, so a delay matters more than it would for an ordinary parcel.
- Order earlier than usual. Ask your pharmacy what its last cold-chain ship date is before each holiday.
- Ask which days it ships. Some pharmacies avoid shipping refrigerated packages late in the week, but policies differ. Ask yours.
- Change the delivery address if needed. A workplace or a neighbor who is home, or a carrier hold-for-pickup option, can cut porch time.
- Watch the beyond-use date. Ordering early helps only if the new vial will still be within its beyond-use date when you need it. For multi-dose vials, FDA advises discarding 28 days after first use (FDA).
Questions to ask your pharmacy
- What are the labeled storage limits for my product, including the lowest temperature it can be exposed to?
- Does my shipment include a temperature or freeze indicator? If not, can it?
- How do you pack for cold weather? Is there insulation between the gel packs and the vial?
- What is your replacement policy for a vial that froze or may have frozen in transit, and what documentation do you need?
- Do you want the affected vial returned, or should I dispose of it?
- What are your last cold-chain ship dates before Thanksgiving, Christmas, and New Year's?
Where this guide stops
This guide can't tell you whether a specific compounded vial is still potent or sterile after cold exposure. That depends on the formulation and on stability data that only the pharmacy has, and FDA has not reviewed it. Approved-product labels are used here as a reference point, not as instructions for compounded products. Carrier holiday schedules can change, so confirm dates with your carrier. Decisions about dosing, missed doses, or switching products belong with your prescriber.
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Frequently asked questions
Can I use compounded semaglutide or tirzepatide that froze?
The FDA-approved labels for semaglutide (Ozempic) and tirzepatide (Mounjaro) say not to use the drug if it has been frozen. Compounded versions have no FDA-reviewed storage data, so set the vial aside and ask the dispensing pharmacy before using it.
If the vial thawed and looks clear, is it fine?
Not necessarily. The approved labels don't make an exception for product that looks normal after thawing. Appearance alone doesn't show whether the drug is still potent, so ask the pharmacy in writing.
What should I document if my GLP-1 shipment may have frozen?
Photograph the box, packing, any temperature indicator, and the vial label with its lot number and beyond-use date, and note the delivery scan time. Keep the vial in the fridge marked 'do not use' until the pharmacy responds.
Which 2026 holidays affect GLP-1 shipping?
Thanksgiving (Thursday, November 26, 2026), Christmas (Friday, December 25, 2026), and New Year's Day (Friday, January 1, 2027) are federal holidays. Check your carrier's holiday schedule and ask your pharmacy for its last cold-chain ship dates.
Sources
- Ozempic (semaglutide) prescribing information, Novo Nordisk
- Mounjaro (tirzepatide) prescribing information, Eli Lilly
- Wegovy (semaglutide) prescribing information, Novo Nordisk (revised 06/2026)
- Zepbound (tirzepatide) prescribing information, Eli Lilly (revised 08/2026)
- FDA: FDA's concerns with unapproved GLP-1 drugs used for weight loss (updated October 1, 2026)
- U.S. Office of Personnel Management: Federal Holidays
Medical disclaimer: This article is general information, not medical advice, and does not replace a licensed clinician who knows your history. Approvals, labels, coverage and prices change; check the linked sources and talk with your prescriber or pharmacist before making decisions about any medication.