Two dates govern a vial of compounded semaglutide. Unopened, it keeps until the beyond-use date the pharmacy printed. Opened, FDA gives it 28 days. The 56-day figure you may have seen belongs to brand pens, not to vials. For what's in a compounded product to begin with, see the compounded semaglutide guide.
Unopened: the pharmacy's beyond-use date
The pharmacy that compounded your semaglutide decides how long it keeps and prints that as a beyond-use date. FDA’s draft guidance for 503B outsourcing facilities describes it as "a date beyond which a compounded drug product should not be used" [4]. FDA does not review compounded drugs for safety, effectiveness or quality before marketing [1]. That differs from saying a pharmacy performs no testing. Follow its storage instructions; a printed date does not establish that a vial remains usable after a storage problem.
Opened: FDA's 28-day limit
Once a multi-dose vial has been used, the clock changes. FDA's reason is contamination: the agency recommends using such vials within 28 days of first use "because there is an increased risk of contamination after 28 days" [1].
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.[1]
That settles the most common question: no, don't keep using a vial past 28 days because some is left. Write the date of your first dose on the box. If you often have medicine left at day 28, raise it with your prescriber rather than stretching the vial. Contamination is one of the compounding risks covered in is compounded semaglutide safe.
Why brand pens get 56 days and vials don't
Ozempic and Wegovy FlexTouch pens carry their own storage rules, set in their FDA-approved labels. After first use, an Ozempic pen "can be stored for 56 days" at 59°F to 86°F (15°C to 30°C) or in the refrigerator [3]. Wegovy FlexTouch also has a 56-day after-first-use limit. Its prescribing-information storage section and device instructions give different room-temperature ranges, so follow the instructions supplied with your pen and ask the pharmacist to resolve any discrepancy [2]. Those figures describe Novo Nordisk's own pens. They don't transfer to a vial that a pharmacy filled.
| Product | Before first use | After first use, or out of the fridge | Source |
|---|---|---|---|
| Compounded semaglutide, multi-dose vial | Until the pharmacy's beyond-use date, stored as its label says | Discard 28 days after first use, even if the label says longer | Pharmacy label; FDA [1] |
| Wegovy single-dose pen or syringe | 36°F to 46°F (2°C to 8°C); up to 28 days at 46°F to 86°F before the cap comes off | One dose, then discard | Wegovy label [2] |
| Wegovy FlexTouch pen | In the refrigerator | 56 days; check the supplied device instructions for temperature limits | Wegovy label [2] |
| Ozempic pen | In the refrigerator, until the expiration date | 56 days at 59°F to 86°F, or in the refrigerator | Ozempic label [3] |
| Ozempic single-dose syringe | Refrigerated; up to 28 days at 46°F to 86°F if needed | One dose, then discard | Ozempic label [3] |
| Wegovy tablets | 68°F to 77°F in the original bottle, away from moisture | Same | Wegovy label [2] |
Brand rules come from the Wegovy and Ozempic labels on DailyMed. FDA's 28-day advice comes from its GLP-1 page, current as of October 1, 2026.
Does it need to be refrigerated?
For injectable semaglutide, assume yes unless your label says otherwise. FDA says injectable GLP-1 drugs "require refrigeration as indicated in their package inserts" [1]. A compounded preparation has no FDA-approved product label; ask the pharmacy for its own written storage instructions. If it doesn't say how long the vial may sit at room temperature, there's no safe figure to borrow from the brand.
If it got warm or froze
FDA has received complaints about compounded GLP-1s arriving warm or packed with too little ice. Its advice is plain: don't use any injectable GLP-1 "that arrives warm or with insufficient refrigeration, as this can affect the drug's quality" [1]. Ask the program for a replacement; a program that ships cold reliably is worth choosing, as how to get compounded semaglutide explains.
Cold can be a problem too. The Wegovy and Ozempic labels both say not to use the drug if it has been frozen, and not to store it next to the refrigerator's cooling element [2] [3]. Call the pharmacy before using a vial that froze. A product that degraded in storage may not deliver the dose on its label, which matters for whether compounded semaglutide works for you.
Drops, lozenges and tablets follow their own labels
If your prescription is for compounded sublingual drops, lozenges or dissolving tablets, obtain storage instructions for that preparation from the pharmacy. Do not transfer an injection’s storage rules to it; it has no FDA-approved product label. The approved Wegovy pill is a different product, stored at 68°F to 77°F in its original bottle to keep moisture out [2]. It's covered in the oral semaglutide guide.
How long semaglutide lasts in your body
If you meant how long it lasts after a dose: semaglutide has an elimination half-life of about one week, which is why it's injected weekly. Wegovy's label says it stays in the circulation for about 5 to 7 weeks after the last 2.4 mg injection [2]. Tirzepatide follows different storage rules, laid out in how long compounded tirzepatide can be out of the fridge.