FIND THE ANSWER. Complete the picture.

Reconstituting peptides means adding a sterile liquid—usually bacteriostatic water—to a freeze-dried powder peptide so it dissolves into a usable liquid solution. Peptides are stored as dry powder because it lasts longer, but they must be mixed with liquid before use.

It depends on whether the compound is a dry powder (lyophilised) or has been reconstituted. Water is what starts the clock.

Dry powder. Freezer at −20 °C or colder for long-term storage, protected from light and moisture. In this form peptides keep for a long time.

Reconstituted. Refrigerated at 2–8 °C, protected from light, and discarded 28 days after the vial is first punctured. Do not freeze a reconstituted vial. Ice formation concentrates everything dissolved in the shrinking liquid fraction and drives the peptide to aggregate — damage you cannot see in the vial — and thawing does not restart the sterility clock.

Date the vial the first time you draw from it, use a new sterile needle on every entry, swab the septum, and keep one vial to one person. The 28 days assumes all of that; see the next answer for where the number actually comes from.

Two separate things limit a reconstituted vial, and they get confused constantly.

1. Contamination. Bacteriostatic water contains 0.9% benzyl alcohol, which slows microbial growth. It does not sterilise, and it will not undo a contaminated entry. The recognised standard for a preserved multi-dose vial is to date it on first puncture and discard it within 28 days — that is the beyond-use date in USP chapter 797 and in CDC injection-safety guidance, and USP chapter 51 tests preservative systems for exactly 28 days and no longer.

2. The peptide breaking down in water. This is compound-specific and there is no general number. Among licensed peptide medicines reconstituted with a preserved diluent, the approved in-use periods run from 7 days — that is tesamorelin, reconstituted with bacteriostatic water — to 60 days for chorionic gonadotropin. Two products containing the same hormone in the same kind of diluent are labelled 30 and 60 days. Those figures exist because each manufacturer ran a stability programme on that exact formulation.

No such study has been published for the compounds we sell. We are not aware of a peer-reviewed stability study of BPC-157, TB-500, ipamorelin, CJC-1295 or retatrutide reconstituted in bacteriostatic water and stored refrigerated. Anyone quoting you a confident figure for these is extrapolating from something else — and note that the bacteriostatic water label itself states no in-use period at all.

So we say 28 days, because it is the shorter and better-sourced of the two clocks. We would rather tell you it is a microbiological limit than dress it up as a measured shelf life for the peptide.

Discard sooner than that if you see cloudiness, floating particles or a yellow or brown colour change in solution — or moisture and unusual clumping in unmixed powder. Unmixed lyophilised powder kept frozen keeps for a long time; it is reconstitution that starts the clock.

All products sold on our website are intended exclusively for laboratory and research use. They are not to be used for human or animal consumption, drugs, medical devices, or any unapproved applications. By placing an order, all customers confirm they are fully informed about applicable government regulations, understand potential health and safety hazards, and accept full responsibility for applying appropriate safety measures.