BPC-157: peptide identity, purity, and stability

What BPC-157 is

BPC-157 is a synthetic peptide of fifteen amino acid residues. Its name is an abbreviation of "body protection compound," and the numbered designation refers to a partial sequence of a larger protein originally characterised in gastric juice. The material supplied for laboratory work is made by solid-phase peptide synthesis rather than extracted from tissue, which is why its documentation looks like that of any other synthetic peptide: a synthesis record, a chromatographic purity determination, and a mass-spectrometry identity confirmation.

The residue sequence, written in the standard single-letter notation, is GEPPPGKPADDAGLV. In three-letter notation that is Gly-Glu-Pro-Pro-Pro-Gly-Lys-Pro-Ala-Asp-Asp-Ala-Gly-Leu-Val. The sequence is worth knowing because it explains most of what appears on an analytical report for this material, including which impurities are likely and why the peptide behaves as it does on a reversed-phase column.

Treat the figures above as orientation, not as a substitute for the report that accompanies a given lot. The certificate for the specific lot in hand is the authoritative record, and where a published report disagrees with this page, the report governs.

Why the sequence predicts the impurity profile

Three features of GEPPPGKPADDAGLV determine what a chromatogram of this peptide tends to look like.

• A proline-rich stretch. Positions three, four, and five are consecutive prolines, with one more at position eight. Proline couples less efficiently than most residues during synthesis, so deletion sequences — chains missing one residue — are the most common synthesis-related impurity in this material. On a chromatogram they usually appear as peaks eluting close to the main peak rather than far from it, because a fifteen-residue chain missing one residue is chemically very similar to the complete chain.
• Two adjacent aspartic acid residues. Positions ten and eleven are both aspartate. Aspartate-containing sequences are prone to forming a cyclic intermediate that can rearrange the backbone, producing a species with the same mass as the parent peptide but different chromatographic behaviour. This matters for interpretation: mass spectrometry alone will not distinguish it, which is one of the clearest practical reasons a report needs both an identity result and a purity result rather than either on its own.
• No cysteine and no methionine. The sequence contains neither of the two residues most vulnerable to oxidation. Oxidation-related impurity peaks, which dominate the degradation profile of many other research peptides, are therefore not the primary concern for this one. Its stability profile is driven by moisture and by the aspartate chemistry above.

For how these peaks are measured and reported, see how to read an HPLC chromatogram.

How identity is established

Purity and identity are separate questions answered by separate instruments, and a report that gives only one of them is incomplete.

Identity can be established two ways, and it is worth knowing which one a given report used. Mass spectrometry measures the mass-to-charge ratio of the ionised peptide and compares the observed mass against the mass calculated from the stated formula. Retention-time matching compares where the main peak elutes against a reference standard run under the same method; agreement is strong evidence of identity for a known sequence, and it is the method reported as HPLC-RTM on a certificate.

Neither settles the aspartate question on its own. Mass agreement does not exclude a rearranged species of identical mass, and retention-time agreement is what would separate them — which is the practical reason the chromatogram is read alongside the identity line rather than instead of it. Arctic Lab Supply's reports state identity as HPLC-RTM, and the chromatogram is published with them so the peak pattern can be read directly.

The same two questions are answered very differently for a 43-residue chain. BPC-157 vs TB-500: what the analytical report shows places the two materials side by side — chain length, formula, theoretical mass, and how each appears in a mass spectrum — so that a report for one cannot be mistaken for a report for the other.

Purity is established by reversed-phase high-performance liquid chromatography. The sample is separated on a column, every component that reaches the detector is integrated, and the purity figure is the area of the main peak as a percentage of all integrated area. A figure quoted without the chromatogram behind it cannot be checked. HPLC purity versus mass-spectrometry identity covers what each result does and does not establish.

Stability and storage of the lyophilized solid

BPC-157 is supplied as a lyophilized solid, and in that state it is comparatively robust. The freeze-drying step removes the water that drives the principal degradation pathways, which is why sealed vials are stored and shipped as a solid rather than in solution.

Two conditions matter for a sealed vial in storage. The first is temperature: colder storage slows every chemical process available to the peptide, and laboratories generally hold long-term stock frozen rather than at ambient temperature. The second, and the one more often underestimated, is moisture. A lyophilized peptide is hygroscopic — it draws water out of the air. A vial brought from cold storage into a warm room will condense atmospheric moisture on and in the solid if it is opened before it has equilibrated to room temperature, and that adsorbed water is what allows the aspartate rearrangement described above to proceed in what is nominally a dry solid.

Stability is a documented property, not an assumed one. A laboratory establishes it by holding material under defined conditions and re-analysing it at intervals, then reporting what changed. Where a supplier states a retest date or a storage condition, ask what data supports it. Storing lyophilized research materials covers the general case.

Scope of this documentation

This page concerns material identification and analytical documentation for laboratory research. It does not recommend personal, human, clinical, therapeutic or veterinary applications. Published research findings do not establish the properties of Arctic stock; use the applicable lot record and its stated methods and limitations.

Reading the batch documentation for a lot

A report describes the lot and sample identified in that document. Confirm the lot on the actual stock before applying a published result to an order. Four checks apply to a BPC-157 certificate in particular:

1. The lot identifier on the report matches the vial label. A report for a different lot describes different material, however similar the two may be. See lot traceability.
2. The identity line names its method and reference. On Arctic Lab Supply's reports identity is confirmed by HPLC retention-time match (HPLC-RTM) against a reference standard; mass spectrometry is not part of these reports, so there is no observed mass to compare with the calculated value of approximately 1,419 g/mol.
3. The chromatogram is present, not just the number. Peaks eluting immediately adjacent to the main peak are the expected signature for a proline-rich sequence, and their size is more informative than the headline percentage on its own.
4. The integrated areas account for the whole run. If the percentages do not total 100, the report should state what was excluded and why.

Lot history on this site

Two BPC-157 lots have been analysed and published so far, roughly six months apart and by two different independent laboratories. The figures below are copied from the published records; the record itself, not this table, is the authoritative document for each lot.

Three things follow from that table. First, the two results are not a trend line: they were produced by different laboratories under their own methods, so the honest comparison is that both lots reported above 99.5% chromatographic purity under the method each laboratory used, not that the second lot is 0.024 points better. Second, the earlier record stays published after the lot it describes has sold through, which is the one property of a documentation library that is expensive to fake and easy to check — open the older record now, then open it again after the next restock. Third, the 10mg strength does not yet have an exact-lot report of its own. Its listing shows the 5mg family record and labels it as a product-family reference, not as a lot match; a report for one strength does not describe another.

Storage as shipped

The material leaves the warehouse in the state described above: a lyophilized solid in a sealed vial, with the lot identifier printed on every vial so it can be matched to its record on arrival. Orders are packed and shipped from Anchorage, Alaska, with a tracking number sent by email once the parcel is with the carrier.

The shipping policy describes the carrier, tracking, and transit expectations; it does not describe a refrigerated service, and a receiving laboratory should not assume one. The practical consequence is that transit is an interval at whatever temperature the carrier route imposed, and it belongs in the receiving log as such. The storage conditions commonly specified once the vial is in the laboratory's hands are the ones set out in storing lyophilized research materials: refrigerated, 2 to 8 °C, for shorter periods, and frozen, around −20 °C, for longer-term holding, per the receiving laboratory's own procedure. Because the dry solid is hygroscopic, the receiving step that matters most is the one already described — let a cold vial reach room temperature before the seal is broken.

Two records close the loop. Match the lot on the label to the lot on the report and file the certificate number with the inventory entry, as the receiving inspection checklist sets out. And if a parcel arrives damaged, incorrect, or incomplete, the policy asks for the report within 48 hours of delivery, which is also the window in which a seal or moisture problem is easiest to document.

Material on this site

Everything on this page can be checked against the pages it describes.

• BPC-157 5mg — the listing for the strength with a current lot report (BCP-2502-B) and the historical BCP-2501-A record.
• BPC-157 10mg — the 10mg listing, which currently carries the 5mg family reference and states so.
• BPC-157 research material — both strengths, identity fields, and published batch documentation on one page.
• Lot BCP-2502-B analytical report — the lot page with the original PDF and the laboratory's verification link.
• Best BPC-157 supplier: a buyer's checklist — six checks to run on any BPC-157 listing, this one included.
• BPC-157 vs TB-500: what the analytical report shows — the two materials compared on paper.

Related documentation