The shelf life of weight loss peptides is not a fixed value. It depends primarily on two key factors: the product’s storage conditions and whether it has been opened/reconstituted.

Unopened Lyophilized Powder
Under standard storage conditions(refrigerated at 2–8°C, protected from light, sealed, dry, and free from drastic temperature fluctuations):The shelf life indicated at the time of manufacture is typically 24–36 months (subject to your product’s production standards and quality inspection report). This is the standard shelf life for lyophilized peptide medications, as the low-temperature environment maximizes their chemical stability.
Under room temperature storage conditions(below 25°C, protected from light and sealed):Unopened powder can also be stored at room temperature for a short period, but its shelf life will be significantly shortened, usually to 3–6 months. If the ambient temperature exceeds 25°C, the shelf life will be further reduced, and the efficacy may degrade prematurely.
Opened/Reconstituted Solution (Usage Phase)
Weight loss peptide powder must be reconstituted with normal saline or a dedicated solvent before use. At this stage, the shelf life is extremely short, which is a key consideration for users:

Opened but not reconstituted

If the powder vial has been opened but no solvent has been added, it must be immediately resealed and returned to refrigerated storage at 2–8°C. The shelf life will be shortened to within 1 month, and prompt use is recommended.
Reconstituted into a solution: This is the stage with the shortest shelf life, whether stored refrigerated or at room temperature:
Refrigerated (2–8°C): Shelf life is 7–14 days.
Room temperature (below 25°C): Shelf life is only 24–48 hours.
If the ambient temperature exceeds 25°C, it is recommended that the reconstituted solution be used within 12 hours. Otherwise, it will become ineffective due to peptide degradation and may even produce allergenic impurities.