Direct answer (40-60 words)
Yes, Wegovy expires. Each pen has a printed expiration date typically 18 to 24 months from manufacture when refrigerated at 36 to 46 F. Once you start using a pen, you have 28 days at room temperature (under 86 F) before it must be discarded, regardless of how much medication is left.
Table of contents
- The 30-second answer
- The two expiration dates you need to track
- Refrigerated vs room-temperature storage rules
- The 28-day clock after first injection
- What happens chemically when Wegovy expires
- Visual inspection: what a good pen looks like vs a bad one
- Travel rules and temperature excursions
- Disposal of expired or used pens
- Compounded semaglutide expiration is different
- FAQ
- Footer disclaimers
The two expiration dates you need to track
Every Wegovy pen has two expiration windows that operate independently.
Check your GLP-1 eligibility
Use our free BMI Calculator to see if you may qualify for provider-reviewed GLP-1 therapy.
Try the BMI Calculator →Window 1: The printed expiration date. This is the manufacturer's date, set at production by Novo Nordisk and printed on the pen label and outer carton. It's typically 18 to 24 months from the manufacturing date and assumes proper refrigerated storage the entire time. After this date, the medication can degrade, and the pen should not be used.
Window 2: The 28-day in-use window. Once you make the first injection from a pen, a different clock starts. From the date of first use, you have 28 days to use the pen, regardless of whether you store it in the fridge or at room temperature after that first injection. After 28 days the pen must be discarded even if it still has medication in it.
The shorter of these two windows applies. If the printed expiration date hits 14 days after your first injection, the printed date controls and you must discard 14 days early. If you start a pen on the 25th of the month and the printed expiration is 8 months away, the 28-day clock controls.
Most patients run into the 28-day rule before the printed expiration. Wegovy pens at the lower doses (0.25 mg, 0.5 mg) contain 4 weekly doses each, so they're typically used up before either deadline.
Refrigerated vs room-temperature storage rules
Before first use (still sealed):
- Store between 36 F and 46 F (2 C and 8 C)
- Keep in the original carton to protect from light
- Do NOT freeze; freezing destroys the medication permanently
- Do not place against the back wall or in the freezer-adjacent shelf where temps can dip
- Do not store on the door, where temperatures fluctuate every time the fridge opens
After first injection:
- Either keep refrigerated (36 to 46 F) OR keep at room temperature (under 86 F / 30 C)
- The 28-day in-use clock runs the same either way
- Store away from direct sunlight, heating vents, and hot car interiors
- Replace the pen cap when not in use to protect from light
The 28-day rule is per pen. Each new pen gets a fresh 28-day window starting at its first injection.
The medication's stability data is published by Novo Nordisk in the Wegovy prescribing information. The 28-day room-temperature window is based on accelerated stability testing showing the active drug stays within potency specs for 28 days at temperatures up to 86 F.
The 28-day clock after first injection
Some practical notes on the 28-day window:
How to track it. Write the date of first injection on the pen label or carton with a permanent marker. Better still, set a phone reminder for day 28. The pen doesn't display this date for you.
What "first injection" means. The clock starts the moment the pen is first activated and a dose is dispensed. Priming the pen (the manufacturer recommends a small priming step before the first dose) counts as the first activation.
What to do at day 28. Discard the pen even if medication remains. Use a sharps container or an FDA-approved disposal program. Do not attempt to "stretch" a pen past 28 days; the in-use sterility and stability data don't support it.
What if you miss a dose during the 28-day window? The pen is still usable for the days that remain. You don't get to extend the 28-day clock by skipping a week. If the missed dose pushes you outside your weekly cadence, follow the missed-dose instructions from your provider rather than improvising.
What if I started a pen, then refrigerated it for 2 weeks? The 28-day clock keeps running. Refrigeration after first use does not pause or extend it. Total in-use time is what matters.
What happens chemically when Wegovy expires
Wegovy contains semaglutide, a long-acting GLP-1 receptor agonist peptide. Peptides are unstable compared to small-molecule drugs. They can degrade through three main pathways:
- Aggregation. Peptide molecules clump together into inactive aggregates. This is what gives expired or temperature-abused semaglutide a cloudy or particulate appearance. Aggregated peptide loses receptor activity (so it doesn't work as well) and can also trigger immune responses (which can cause injection-site reactions or, rarely, antibody formation).
- Oxidation. Certain amino acids in semaglutide can oxidize, especially when exposed to light or trace metal contamination. Oxidized peptide has reduced binding to GLP-1 receptors.
- Hydrolysis. The peptide bond can break, fragmenting the molecule into smaller, inactive pieces.
The 28-day in-use window is set conservatively. The medication doesn't immediately become dangerous on day 29, but it has likely lost a small but measurable amount of potency by then, and the cumulative risk of aggregation and contamination has increased. By the printed expiration date, the manufacturer no longer guarantees the dose you're injecting matches the dose on the label.
The practical translation: an expired pen probably won't poison you. It might just not work. For a weight-loss medication, that means slower or no progress, plus the disappointment of finding out at your next weigh-in.
Visual inspection: what a good pen looks like vs a bad one
Before every injection, check the medication through the pen window.
A healthy pen contains liquid that is:
- Clear (you can see through it)
- Colorless (no yellow, brown, or pink tint)
- Free of visible particles or floating debris
- Free of crystals on the cartridge wall
Discard the pen if the liquid is:
- Cloudy or hazy
- Discolored (any tint other than colorless)
- Contains visible particles (specks, fibers, crystals)
- Has a meniscus or bubble layer that looks separated rather than uniform
A well-stored, in-date pen rarely shows any of these issues. If it does, the medication has likely degraded or been contaminated. Don't inject it. Contact the pharmacy that dispensed it; many will replace a clearly defective pen.
If you've recently moved, traveled, lost power, or had a fridge issue, do a careful visual check of all your stored pens before use.
Travel rules and temperature excursions
Day trips and short flights. Wegovy can sit at room temperature for short periods without harm. The 28-day rule applies once a pen is in use. For unopened pens, brief room-temperature exposure (under 24 hours) is generally fine, though the manufacturer's official guidance is to keep refrigerated when possible.
Long flights and travel days. Use an insulated medication travel case with a small ice pack. Do not let the pen come in direct contact with the ice pack (this can freeze the medication, which permanently damages it). A thermal sleeve between pen and ice pack is the standard approach.
Checked vs carry-on luggage. Always carry-on. Cargo holds can drop below freezing or rise above 100 F depending on the route. TSA allows medication, including injectables, in carry-on bags.
Hot climates. A car in summer can hit 130 F within 20 minutes. Never leave Wegovy in a parked car, even briefly. If you'll be in temperatures above 86 F for more than a few hours, use a cold pack and insulated case.
Power outages. Refrigerated pens are usually fine through a 4 to 6 hour outage if the fridge stays closed. Beyond that, transfer to a cooler with ice (with thermal protection between pen and ice). After a longer outage, inspect the pens visually and consider whether the temperatures stayed in range.
Frozen pens. A pen that has frozen, even once, even briefly, must be discarded. Freezing damages the peptide structure and may cause aggregation that's invisible without lab analysis. The visible-particle check may not catch all freeze damage.
Disposal of expired or used pens
Wegovy pens contain a needle, even after use. They're considered medical sharps and need to be disposed of properly.
FDA-approved sharps containers are the standard. They're available at most pharmacies and online, and they're designed to prevent needle-stick injuries during disposal.
DIY containers (heavy plastic detergent or laundry bottles) are acceptable in a pinch. Make sure the container is puncture-resistant, leak-proof, and clearly labeled "DO NOT RECYCLE / SHARPS."
What to do with a full sharps container:
- Many pharmacies (CVS, Walgreens, independent pharmacies) accept sharps containers for disposal
- Some local health departments run drop-off programs
- Mail-back disposal services exist for a fee
- Never throw a sharps container in regular trash or recycling
Never:
- Recap a used needle (risk of needle-stick injury)
- Toss a pen in regular household trash
- Flush medication down the toilet
- Burn or incinerate at home
The Wegovy patient information sheet has additional disposal guidance specific to your area. The FDA also maintains a list of approved sharps disposal options.
Compounded semaglutide expiration is different
Compounded semaglutide is not the same product as Wegovy. The expiration rules differ in two important ways.
Different beyond-use date (BUD). Compounded medications are assigned a BUD by the compounding pharmacy, based on USP guidelines and the specific formulation. Typical BUDs for compounded semaglutide range from 28 to 90 days when refrigerated. The compounding pharmacy prints this date on the vial label.
Different storage requirements. Most compounded semaglutide is dispensed as a multi-dose vial rather than a pre-filled pen. Refrigeration is typically required throughout, including after first puncture. Room-temperature stability data for compounded preparations is usually shorter than for Wegovy, sometimes only 7 to 14 days.
For more on compounded semaglutide, see related guide for visual inspection guidance and related guide for the related tirzepatide pricing breakdown.
Compounded semaglutide is not FDA-approved and is not interchangeable with Wegovy. Patients using compounded medications should follow the specific instructions on their pharmacy's label rather than applying Wegovy rules directly.
Edge cases and common questions
My pen sat out overnight by accident. If room temperature stayed below 86 F for under 24 hours, the pen is likely still good. The Wegovy stability data accommodates brief excursions. Inspect visually and use within the regular timeline. If it sat in direct sun or near a heat source, discard.
My fridge died for 8 hours. If the fridge was opened minimally and the medication stayed below 46 F for that period, it's likely fine. If temps rose meaningfully (you can check by feeling whether items are still cold), inspect and consider whether to discard.
I missed a dose because the pen looked off, can I get a replacement? Some pharmacies replace pens that arrived defective. Compounding pharmacies and brand-name pharmacies have different policies. Call before assuming.
The pen feels different (heavier, lighter, has resistance) than my last one. A noticeable change in pen behavior can signal a defective device. Don't force the injection. Contact your pharmacy.
I see a tiny air bubble in the cartridge. A small air bubble is normal and doesn't affect dosing. The pen mechanism dispenses a measured volume of liquid, not air. If the bubble is large enough to interfere with reading the medication, contact your pharmacy.
When to contact a provider
- Suspected injection of expired or visibly degraded medication, with new or unusual symptoms
- Persistent injection site reactions that started after a specific pen
- Doubt about whether a pen is safe to use after a temperature excursion or storage issue
- Repeated supply problems (defective pens arriving, frequent mismatches between expected and printed dates)
For routine storage questions, the prescribing pharmacy is usually the faster contact point. For symptom-related questions, the medical provider who prescribed Wegovy is the right person.
FAQ
Does Wegovy expire?
Yes. Each pen has a printed manufacturer expiration date (typically 18 to 24 months from production when refrigerated) and a 28-day in-use clock that starts at the first injection. Whichever is shorter applies.
How long does Wegovy last after I open it?
28 days from the first injection, whether stored in the fridge or at room temperature (under 86 F) afterward.
Can Wegovy be left at room temperature?
Yes, briefly before first use, and for up to 28 days after first use as long as the temperature stays under 86 F. Long-term storage before use should be refrigerated.
What if I accidentally froze my Wegovy pen?
Discard it. Freezing permanently damages the peptide structure. Even brief freezing can cause aggregation. Don't use it.
Can I still use Wegovy if it looks cloudy?
No. Cloudy or particulate liquid means the medication has degraded or been contaminated. Don't inject. Contact your pharmacy for guidance and possible replacement.
Where should I store my Wegovy?
In the main body of the refrigerator, in the original carton, between 36 and 46 F. Avoid the door (temperature fluctuations) and the back wall (freezing risk).
How do I dispose of an expired Wegovy pen?
In an FDA-approved sharps container. Many pharmacies will accept a full container for disposal. Never throw a used or expired pen in regular trash.
Does the 28-day window restart if I refrigerate the pen?
No. The 28-day clock runs from the date of first injection regardless of subsequent storage temperature.
Can I travel with Wegovy?
Yes. Use an insulated medication travel case with a cold pack (with thermal protection between pen and ice). Carry-on only, never checked luggage.
What's the temperature range for Wegovy refrigeration?
36 to 46 F (2 to 8 C). Below 36 F risks freezing damage. Above 46 F shortens the medication's stability.
Do compounded semaglutide pens have the same 28-day rule?
Not necessarily. Compounded medications have a beyond-use date set by the compounding pharmacy, which can be shorter or different from Wegovy's rules. Follow the specific instructions on your pharmacy label.
Is it okay to inject Wegovy that's been stored too warm?
If the temperature stayed under 86 F and the duration was within stability limits (28 days post-injection, brief excursions before that), yes. If temperatures exceeded 86 F or the medication looks abnormal, discard.
What if my Wegovy expires before I finish it?
Discard the unused medication and start a new pen. Don't extend the use of an expired pen.
Author / review note
Reviewed by the FormBlends Medical Team. References include the Wegovy prescribing information (Novo Nordisk, 2024), the FDA guidance on safe sharps disposal, USP Chapter <797> on pharmaceutical compounding standards, and Novo Nordisk's published stability data for semaglutide formulations.
Footer disclaimers (all 4 verbatim)
Platform Disclaimer. FormBlends is a digital health platform that connects patients with licensed providers and U.S.-based pharmacies. We do not manufacture, prescribe, or dispense medication directly. All clinical decisions are made by independent licensed providers.
Compounded Medication Notice. Compounded semaglutide and tirzepatide are not FDA-approved. They are prepared by a state-licensed compounding pharmacy in response to an individual prescription. Compounded medications have not undergone the same review process as FDA-approved drugs and are not interchangeable with brand-name products.
Results Disclaimer. Individual results vary. Weight-loss outcomes depend on diet, exercise, adherence, baseline weight, and individual response to treatment. Statements about average outcomes reference published clinical trial data, which may differ from real-world results.
Trademark Notice. Wegovy is a registered trademark of Novo Nordisk A/S. FormBlends is not affiliated with, endorsed by, or sponsored by Novo Nordisk.
Talk to a licensed provider
Start your free assessment. A licensed provider reviews every request before anything is prescribed, and not everyone qualifies.
Start the assessment →