Storing a GLP-1 pen: the fridge, the counter, and the day count

By Ümit Can Erim · Published 18 August 2026 · Updated 18 August 2026 · Sources checked 18 August 2026 · How these guides are written

Unopened, they all live in the fridge at 2–8 °C. What differs is what happens after that, and it differs by pen, not only by medicine: the same product can give you 56 days in one device and 28 in another. One of them must never go back in the fridge once it has been out. This page quotes each label and names the source.

Read this first. These are quotations from public drug labelling, not a judgement about the pen in your fridge. This page cannot tell you whether a particular pen is still fit to use: nothing written in advance can, because it depends on how warm it got and for how long. If you are unsure, ask your pharmacist. They can look at the actual product and give you an actual answer, and it costs nothing.

Two questions, not one

Storage instructions answer two separate things, and mixing them up is where most of the confusion comes from. Before first use is about the shelf life of a sealed product: refrigerated, in its carton, until the expiry date printed on it. After first use (or, for single-dose devices, after it leaves the fridge) is a much shorter clock that starts the moment the product is in play, and it is the number people actually need.

The second clock is the one that varies. It varies between medicines, and it varies between the devices a single medicine is sold in.

What each label says

Semaglutide, multi-dose pen (Ozempic®; Wegovy® FlexTouch)

Before first use: refrigerated at 2–8 °C (36–46 °F), in the original carton, not in the freezer and not directly against the cooling element. After first use: 56 days, either at controlled room temperature 15–30 °C (59–86 °F) or back in the fridge. Cap on when not in use, needle removed after every injection, and away from excessive heat and sunlight.

Semaglutide, single-dose pen or syringe (Wegovy®; Ozempic® prefilled syringe)

Same fridge range, different clock: if needed, and before the cap comes off, it can be kept at 8–30 °C (46–86 °F) in its carton for up to 28 days. The Wegovy labelling says to throw the device away if it has been frozen, exposed to light or to temperatures above 30 °C, or has been out of the fridge for 28 days or longer: or after use, since it is a single dose.

Tirzepatide (Mounjaro®, Zepbound®)

Refrigerated at 36–46 °F, kept in the original carton to protect it from light. Room temperature is allowed for 21 days if needed, and then the rule that catches people out: do not return it to the refrigerator once it has been stored at room temperature. This one is a one-way door.

Dulaglutide (Trulicity®)

In the original carton in the fridge, protected from light, not frozen. If necessary, each prefilled pen can be kept at room temperature for up to 14 days — the shortest window of the weekly injections here.

Liraglutide (Saxenda®, Victoza®)

Unused pens go in the fridge at 2–8 °C (36–46 °F). Once a pen is in use the instruction is phrased as a hard stop rather than a range: throw the pen away after 30 days, even if there is solution left. Do not freeze, and do not use it if it has been frozen or exposed to temperatures above 30 °C (86 °F).

Tablets (Rybelsus®; Wegovy® tablets)

No fridge at all. Room temperature, in the original closed container, away from excess heat and moisture, which rules out the bathroom cabinet, the one place a lot of medicine ends up. The Wegovy tablet labelling gives a narrower range: 20–25 °C (68–77 °F).

The pattern worth remembering

Two things repeat across all of them. First, frozen is final: every label says not to freeze and not to use a product that has been frozen, with no window and no judgement call. Second, the day count is a maximum, not a target, nothing says a pen is better for having spent its 56 days on a worktop, only that it is still within instructions if it did.

And the one that is genuinely easy to get wrong: tirzepatide's room-temperature period cannot be undone by putting it back in the cold.

Knowing which day you opened it

Every one of these numbers counts from a day, and that day is the one nobody writes down. A pen in the door of the fridge does not say when it was first used, and "about three weeks ago, I think" is not a date you can subtract from. Recording the day a pen is opened turns all of the above from a calculation into a number on a screen, and it is the same record that tells you the vial will run out before the weekend the pharmacy is closed.

Dozify counts the days from the day you opened it

Doses left, days since opening and the expiry date on one card, with the storage rules for that medication beside them. Log an afternoon out of the fridge as a storage event and it stays on the vial's record.

Download the app See how vial tracking works →

Questions

My pen was left out overnight. Is it ruined?

Not necessarily, every product here allows some time out of the fridge, and one night is well inside all of those windows if the room was not hot. What matters is the temperature it reached and how long, and whether this is the first time. That judgement belongs to your pharmacist, who will ask you exactly those questions.

Can I put it back in the fridge after a trip?

For semaglutide pens the labelling describes both room temperature and the refrigerator as options during the in-use period. For tirzepatide it says the opposite in as many words: do not return it to the refrigerator if it has been stored at room temperature. Check which one you have.

It froze at the back of the fridge. Can I still use it?

No. This is the one place the labels leave no room at all: do not use a product that has been frozen. That is why they also say not to store it directly against the cooling element, which is where a fridge is coldest.

Ozempic® and Wegovy® are both semaglutide. Why 56 days and 28?

Because the number follows the device, not the molecule. A multi-dose pen you inject from for weeks gets 56 days from first use; a single-dose pen or syringe gets up to 28 days out of the fridge before its cap comes off. Wegovy is sold in both forms, and so is Ozempic, so the answer is on your carton, not on the brand.

Does the expiry date on the box still apply once I open it?

Both apply, and whichever comes first is the one that ends it. An in-use window that runs past the printed expiry does not extend it.

Educational information, not medical advice. Dozify is a personal tracking app, not a medical device. This page quotes public drug labelling and does not judge whether any particular product is safe to use. Always follow the instructions that came with your medication, and ask your pharmacist or prescriber when you are unsure.