BPC-157 Research Guide: Structure, COA, Acetate vs. Arginate and Handling
BPC-157 is a synthetic 15-amino-acid peptide based on a sequence from a protein found in gastric juice. It is one of the most widely studied research peptides, used mainly in rodent models of soft-tissue and gastrointestinal injury. This page covers its structure, the acetate vs. arginate salt question, what a BPC-157 certificate of analysis should show, and how to handle the lyophilized powder, using FRO Peptides’ two published lot reports as examples.
BPC-157 at a glance
| Full name | Body Protection Compound-157 (pentadecapeptide BPC 157) |
|---|---|
| Sequence | Gly-Glu-Pro-Pro-Pro-Gly-Lys-Pro-Ala-Asp-Asp-Ala-Gly-Leu-Val (GEPPPGKPADDAGLV), 15 amino acids |
| Molecular formula | C62H98N16O22 |
| Molecular weight | ≈ 1,419.5 g/mol |
| CAS number | 137525-51-0 |
| Supplied as | Lyophilized white powder in sealed vials |
| FRO vial sizes | 5mg, 10mg |
| FRO tested purity | 98.59% (5mg, HG8J-P5ZK) and 98.2% (10mg, N7Y9-66RZ), HPLC |
Where BPC-157 comes from
BPC-157 was developed by a research group at the University of Zagreb, Croatia, from a larger protein they isolated from human gastric juice and named “body protection compound.” The 15-residue fragment is the part they found to be stable and active in their models, and it is made synthetically. Unlike many research peptides, it is reported to be stable in gastric acid, which is part of why it is studied in gastrointestinal models.
The sequence is unusual: four prolines in the first eight residues. Proline-rich stretches resist enzymatic cleavage and make the chain fairly rigid, which helps explain its stability in lab conditions.
Why labs study it
- Soft-tissue injury models. Published rodent studies use it in models of tendon, ligament and muscle injury.
- Gastrointestinal models. Given its origin, it is studied in models of gastric and intestinal lesions.
- Angiogenesis and nitric oxide signaling. Researchers use it to study new blood-vessel formation and interactions with the nitric oxide system and VEGF receptor signaling.
Worth knowing: most of the published BPC-157 literature comes from the original Zagreb group, and it is overwhelmingly animal and cell work. Independent replication is still limited, so treat it as a research compound under active study.
BPC-157 acetate vs. arginate
Peptides are made as salts, and the salt form is set by the last purification step. Most BPC-157 on the research market is the acetate salt, the standard form for lyophilized peptides. Some suppliers sell an arginate salt (BPC-157 Arg), marketed as more stable in solution. The peptide chain is the same in both, but the salt changes the weight of each vial that is actual peptide, so the two are not directly interchangeable by milligram. FRO’s COAs confirm identity, purity and measured quantity, and don’t state a salt form. If your protocol depends on it, ask before ordering.
How to read a BPC-157 certificate of analysis
A COA is only useful if you know what each line proves. FRO has two BPC-157 reports on file from AccuMark Labs, both received 02/24/2026 and published 09/07/2026:
| Test | 5mg (HG8J-P5ZK) | 10mg (N7Y9-66RZ) | What it tells you |
|---|---|---|---|
| Identity | BPC-157, conforms | BPC-157, conforms | The main compound in the vial matches BPC-157. |
| HPLC purity | 98.59% | 98.2% | Share of the sample that is the target peptide, measured by UV at 220 nm, against a spec of more than 98.0%. Both chromatograms show one main peak at about 3.4 minutes. The dip near 1 minute is the solvent front. |
| Quantity | 6.05 mg in a 5 mg vial | 11.13 mg in a 10 mg vial | How much peptide is actually in the vial. Both lots were overfilled, by about 21% and 11%. Many COAs skip this line, but it is the one that catches underfilled vials. |
Both lots clear the purity spec. Both full reports, chromatograms included, are free to open in the BPC-157 COA library. Match the code on your vial to the right report.
What these reports don’t cover
These reports cover identity, HPLC purity and measured quantity. They don’t include endotoxin, sterility, mass spectrometry or salt form. Mass spectrometry would confirm the exact molecular weight of 1,419.5. FRO has BPC-157 testing underway at Vanguard Laboratory, an ISO 17025 lab, and the results will be added to the COA library when they come in.
Red flags on any supplier’s BPC-157 COA
- No lot or sample code, or a code that doesn’t match the vial.
- No lab name, or a lab you can’t find.
- Purity with no chromatogram.
- No measured quantity, only the label claim.
- One report covering every vial size, when the sizes are filled from different lots.
- The same report reused across several products or years.
Storage and handling for research use
- Lyophilized powder: store frozen (−20 °C), sealed and protected from light. Let the vial reach room temperature before opening to avoid condensation.
- Reconstitution: BPC-157 is water-soluble. Add bacteriostatic water slowly down the vial wall and swirl gently until clear. Use the peptide reconstitution calculator to work out concentration for your protocol.
- After reconstitution: refrigerate at 2–8 °C, protect from light, and use within your protocol’s defined window.
- Avoid repeated freeze-thaw. If you need to store reconstituted material frozen, split it into single-use aliquots first.
Frequently asked questions
Does FRO Peptides publish a COA for BPC-157?
Yes, one for each vial size. Both reports from AccuMark Labs, an independent lab, are in the COA library, chromatograms included.
What purity is FRO’s BPC-157?
The 5mg lot tested at 98.59% and the 10mg lot at 98.2% by HPLC, both against a specification of more than 98.0%.
Is FRO’s BPC-157 acetate or arginate?
The current COAs don’t state a salt form. Contact FRO before ordering if your protocol needs a specific salt.
Can I get BPC-157 combined with TB-500?
Yes. The Wolverine Stack combines BPC-157 and TB-500 in one vial, the Glow blend adds GHK-Cu, and KLOW adds GHK-Cu and KPV. Each has its own lot report. See the TB-500 research guide for that compound.
Is BPC-157 from FRO for human use?
No. FRO sells BPC-157 strictly for laboratory and analytical research. It is not for human or veterinary use.
View BPC-157 research peptide (5mg, 10mg) →
Lot reports for both sizes published in the COA library. Ships next business day, FedEx 2-Day.
For laboratory research use only. Not for human or veterinary use. Not a drug, food, or cosmetic under FDA regulations. Nothing on this page is medical advice.