Short answer: the number you see everywhere, “about 4 weeks in the fridge,” is a reasonable working rule for reconstituted BPC-157 in bacteriostatic water. But it is worth knowing where it comes from, because it is not a BPC-157 study. No one has published a stability study of BPC-157 in solution. The 28-day figure comes from pharmacy sterility rules for opened multi-dose vials. The good news is that BPC-157’s chemistry is on your side: it lacks the amino acids that usually make peptides fall apart fastest. Here is what we know, what we assume, and how to store it so the assumption holds.
Need the numbers? Our free peptide reconstitution calculator gives you the concentration and volume for any vial size.
The quick reference table
| Form | Where | Common working guidance | What it is based on |
|---|---|---|---|
| Lyophilized powder, sealed | Freezer (−20 °C) | Long term, often 1–2 years or more | General peptide chemistry; dry peptides degrade very slowly |
| Lyophilized powder, sealed | Fridge (2–8 °C) | Several months | Same |
| Lyophilized powder, sealed | Room temperature | Weeks (shipping is fine) | Same |
| Reconstituted in bacteriostatic water | Fridge (2–8 °C) | About 28 days | Pharmacy multi-dose sterility rule, not a BPC-157 study |
| Reconstituted in sterile water | Fridge (2–8 °C) | Single use; 24 hours at most | No preservative, so contamination risk rises with each puncture |
| Reconstituted, any diluent | Room temperature | Avoid | Heat speeds both chemical breakdown and microbial growth |
For the full storage picture, including the mistakes that ruin vials before they are opened, see how to store peptides.
Where “28 days” really comes from
In pharmacies, USP chapter <797> sets a default 28-day limit for an opened multi-dose vial that contains an antimicrobial preservative, unless the manufacturer specifies otherwise. Bacteriostatic water is exactly that: sterile water with 0.9% benzyl alcohol as a preservative. So the 28-day number is about keeping a punctured vial free of microbes.
That is a different question from whether the peptide itself is still intact. In practice the two limits tend to line up for a sturdy peptide, which is why 28 days is a sensible working window. Just know that it is a borrowed rule, not a measured shelf life for BPC-157.
Why BPC-157 is a relatively sturdy peptide
BPC-157 is 15 amino acids long: G-E-P-P-P-G-K-P-A-D-D-A-G-L-V. Peptides in solution usually break down through a few well-known routes, and each route needs specific amino acids to start.
| Breakdown route | Amino acids that trigger it | In BPC-157? |
|---|---|---|
| Oxidation | Methionine, cysteine, tryptophan | None present |
| Deamidation | Asparagine, glutamine | None present |
| Aspartate isomerization and cleavage | Aspartic acid, especially before glycine | Two aspartates (D-D-A), not followed by glycine: slower route |
| Hydrolysis of the backbone | Any peptide, faster with heat and extreme pH | Possible, slow when cold |
That profile is why BPC-157 has a reputation for being robust. Its developers in Zagreb have also reported that it remains stable in human gastric juice for more than 24 hours, which is unusual for a peptide. None of this replaces a real stability study, but it does mean the 28-day working rule is unlikely to be wildly optimistic when the vial stays cold.
Bacteriostatic vs sterile water changes everything
The diluent decides the clock more than the peptide does. Bacteriostatic water’s benzyl alcohol stops bacteria from multiplying between punctures, so a multi-use vial stays clean for weeks. Sterile water has no preservative: once punctured, anything that gets in can grow. That makes sterile water a single-use diluent. We cover the full comparison in bacteriostatic water vs sterile water, and the step-by-step lab method in how to reconstitute peptides.
Can you freeze reconstituted BPC-157?
In the lab, yes, with one rule: freeze it once. Ice crystals and repeated freeze-thaw cycles stress peptides and can cause aggregation. The standard approach is to split the solution into single-use aliquots, freeze them at −20 °C or colder, and thaw each one only when needed. Do not refreeze a thawed aliquot, and do not keep a whole reconstituted vial going in and out of the freezer.
Signs a solution has gone bad
- Cloudiness in a solution that was clear.
- Particles, flakes or film on the glass.
- Colour change. BPC-157 solution should be colourless.
- The vial was left warm for hours, or frozen and thawed repeatedly.
The catch: a clear solution is not proof of a good one. Chemical breakdown is invisible. Only testing (HPLC) can tell you how much intact peptide is left. If in doubt, discard it, and start from a batch with a proper COA. Our COA guide shows what to check.
See TrueLabs bacteriostatic water →
Frequently asked questions
Cliquez sur une question pour afficher la réponse.
How long does reconstituted BPC-157 last?
A common working rule is about 28 days refrigerated at 2–8 °C when reconstituted with bacteriostatic water. That figure comes from pharmacy sterility rules for multi-dose vials; no published study has measured BPC-157 stability in solution.
Does BPC-157 need to be refrigerated?
Once reconstituted, yes. Lyophilized powder tolerates room temperature for shipping, but long-term storage should be in the freezer, and any solution should be kept at 2–8 °C.
How long does BPC-157 powder last?
Sealed lyophilized BPC-157 stored at −20 °C is commonly kept for one to two years or more. In the fridge it keeps for months, and at room temperature for weeks.
Can you freeze reconstituted BPC-157?
Yes, if you split it into single-use aliquots first and freeze each only once. Repeated freeze-thaw cycles can damage peptides.
How do I know if BPC-157 has gone bad?
Discard it if it becomes cloudy, shows particles or changes colour, or if it was left warm. A clear solution can still be degraded, since chemical breakdown is invisible without testing.
Does reconstituted BPC-157 last longer in sterile water?
No. Sterile water has no preservative, so it should be treated as single use. Bacteriostatic water is the standard diluent for vials used more than once.
Related reading
- How to reconstitute peptides: the complete lab guide
- Bacteriostatic water vs sterile water
- How to store peptides: 6 mistakes to avoid
References
- United States Pharmacopeia. General Chapter <797> Pharmaceutical Compounding: Sterile Preparations (multiple-dose container beyond-use dates). USP
- Manning MC, Chou DK, Murphy BM, Payne RW, Katayama DS. Stability of protein pharmaceuticals: an update. Pharm Res. 2010;27(4):544–575. PubMed
- Sikiric P, et al. Stable gastric pentadecapeptide BPC 157: novel therapy in gastrointestinal tract. Curr Pharm Des. 2011. PubMed
All TrueLabs products are sold for in vitro and laboratory research use only. They are not intended for human or veterinary use, and nothing in this article is medical advice.