Drug facts

How long compounded semaglutide lasts

By David Chen·Editor·Reviewed September 2026

The approved storage range¹

Refrigerated

2°C to 8°C (36°F to 46°F)

Single-dose pen or syringe

Up to 28 days at 8°C to 30°C (46°F to 86°F)

FlexTouch, after first use

Up to 56 days at 15°C to 30°C (59°F to 86°F)

Freezing

Never — discard if frozen

Two further instructions travel with those numbers and are easy to lose: keep it away from light, and keep it in the original carton until the moment of administration. The label also says not to store it directly against the cooling element at the back of a fridge, which is where things freeze without anyone intending it.

The room-temperature allowance is a total, not a nightly budget. Time out of the fridge accumulates over the life of the device; it does not reset when it goes back in.

Why a compounded vial is different¹

So the numbers above are the wrong ones to apply to a compounded vial, even though they are the ones every search result returns. Whatever your own label says, that is the date — and if it is missing, that is worth asking about before anything else.

Does compounded semaglutide expire?³

Yes, and it can expire in two ways. The first is the beyond-use date the compounding pharmacy prints on the label. The second starts when you first pierce the stopper: FDA says to discard a multi-dose vial 28 days after first use. Whichever comes first is the day the vial is finished, even if medicine is left in it.

Unopened compounded vial

Good until the pharmacy’s beyond-use date, stored as the pharmacy directs

Opened compounded vial

The beyond-use date or 28 days after first use, whichever is earlier

Approved Wegovy pen

The expiration date (EXP) printed on it, within the fridge and room-temperature limits above

The approved pen has its own rule on expiry: its instructions for use say not to use it if the expiration date has passed.⁴ A compounded vial has no manufacturer’s expiration date to read, which is why the pharmacy’s beyond-use date matters so much. If the vial or its label shows none, ask the pharmacy before using it.

The storage rules exist to keep the drug intact up to that date: the approved label says to refrigerate it, protect it from light and never freeze it. A vial past either date is not one to stretch, and the questions below cover the fridge and warm deliveries.

The 28-day rule³

“Does compounded semaglutide expire after 28 days?” is one of the most searched questions about it, and FDA has answered it directly. For a vial that holds several doses:

Discard the vial within 28 days after the first use, even if medication remains in the vial. Do not continue using medication from the vial after 28 days, even if instructions from the compounder say the medication can be used for longer than 28 days.

So yes — in the sense that matters. The clock starts when the stopper is first pierced, because every draw is another chance for contamination, and FDA’s limit overrides a longer one on the label. The pharmacy’s beyond-use date still applies too: whichever of the two comes first is the day the vial is finished.

That also changes the arithmetic of a big vial. If a vial holds more than four weeks of doses at your current strength, the rest is discarded on day 28 — worth knowing when a seller prices by the vial rather than by the month, which is the kind of billing the index restates.

If your vial has been out of the fridge²

If it arrived that way, FDA’s advice is not to use it: the agency recommends against using any injectable GLP-1 drug that arrives warm or with insufficient refrigeration, because it can affect the drug’s quality.³ Ask the seller for a replacement.

If it has been out since, there is no chart that answers this, and a page that offered one would be guessing. What determines the answer is the preparation, its preservative if it has one, how warm it got and for how long — and none of that is knowable from here.

The pharmacy that made it is the only party that can answer, and it is a reasonable thing to call and ask. If a seller will not answer a question about the vial it shipped you, that is itself an answer of a kind — see the four checks.

Whether a particular vial is still good is a question for the pharmacy that dispensed it. A pink or red tint may be an add-in; see B12, B6 and glycine.