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A reconstituted peptide vial’s beyond-use date (BUD) is the day you should stop using it and discard it. For a refrigerated, reconstituted multi-dose vial a common benchmark is 28 days, following USP Chapter 797. Enter the date you mixed your vial to get the exact discard date and the days remaining — reference math, not medical advice.
| Vial state & storage | Typical beyond-use window |
|---|---|
| Reconstituted, refrigerated (36–46 °F / 2–8 °C) | 28 days (USP <797> default for multi-dose) |
| Reconstituted, room temperature | Shorter — often days; follow the product COA |
| Lyophilized (unmixed), cold storage | Until the manufacturer expiry date |
USP <797> assigns a 28-day beyond-use date to a refrigerated multi-dose sterile preparation after first entry when there is no product-specific stability data. Storage temperature, preservative, and the manufacturer's Certificate of Analysis can change this. Reference math only — not medical advice; follow your product label and a clinician.
Frequently asked questions
What is a beyond-use date (BUD) for a reconstituted peptide?
The beyond-use date is the point after which a mixed (reconstituted) vial should no longer be used and should be discarded. It reflects how long the solution is expected to stay stable and reasonably protected from contamination once bacteriostatic water has been added — it is not the manufacturer’s expiry date printed on the dry, unmixed powder.
How long does reconstituted semaglutide or tirzepatide last in the fridge?
A widely used benchmark is 28 days refrigerated at 36 to 46 °F (2 to 8 °C), which follows the USP Chapter 797 default beyond-use date for a multi-dose sterile preparation after first entry when there is no product-specific stability data. Some products publish their own figure on the Certificate of Analysis or label — use that when it is available.
Where does the 28-day number come from?
USP General Chapter 797 assigns a 28-day beyond-use date to refrigerated multi-dose sterile preparations after they are first entered, in the absence of product-specific stability testing. It is a conservative default rather than a guarantee — storage temperature, light, and the preservative in the diluent all affect real-world stability.
Does storage temperature change the beyond-use date?
Yes. Refrigeration at 36 to 46 °F (2 to 8 °C) generally supports the longest window; storing at room temperature is shorter, often only days. Freezing is not appropriate for many reconstituted peptides and can degrade them. Always follow the storage instructions on your product’s label or Certificate of Analysis.
Is this calculator medical advice?
No — it is date arithmetic and reference information only. It does not test your specific vial, assess sterility, or tell you whether a product is safe to use. Confirm handling and storage with the product label, a pharmacist, or a clinician.