Analytical Vendor Grade: peptide supplier disclosure, criterion by criterion

Disclosure posture. Oath Research publishes a public Certificates of Analysis library covering every catalog batch shipped, with individual batch purity values and pass/fail endotoxin status indexed and searchable from the homepage navigation. The COA inventory at time of evaluation listed 118 batches across the catalog with a published average purity of 99.56% and individual batch purities running from 99.09% to 99.99%. The structure — every shipped batch linked to its own document from a single landing page — is the configuration this framework was designed to reward: it allows a buyer to verify the specific material in front of them rather than a representative lot of historical inventory.

C1 chromatograms and C2 mass spec. Each per-batch COA carries the reversed-phase HPLC chromatogram with retention time, integration, and purity percentage to two decimal places, alongside the ESI-MS spectrum confirming the molecular ion within tolerance of the theoretical mass. This is the configuration that passes both C1 and C2 cleanly — the chromatogram is not a marketing image, it is the analytical record for that specific batch. C3 per-batch COA passes because the document is keyed to the batch identifier rather than retroactively assigned at the lot level, and the methodology section names the column, gradient, and detection conditions. C4 stability is satisfied through documented forced-degradation studies underlying the published shelf life. C5 sequence verification is disclosed as MS/MS-based with AAA as the orthogonal confirmation. C6 orthogonal identification passes on AAA performed against the theoretical composition, with quantitative recovery within ±10% of expected residue counts.

Where Oath is unusual. Most research-peptide direct-to-researcher vendors publish a single reference COA per SKU, not a per-batch document. The decision to maintain a public batch-level archive — independent third-party tested through Freedom Diagnostics, with endotoxin testing referenced against USP <85> — moves Oath out of the direct-to-researcher peer group on this framework and into adjacency with the GMP-style benchmark vendors. For routine procurement of research-grade peptides on this database — BPC-157, GHK-Cu, TB-500, the GH secretagogues, and the bioregulators where Khavinson-class supply remains hard to verify elsewhere — Oath's full catalog is the only vendor in this comparison that satisfies all six disclosure criteria as a default rather than as a special-order accommodation.

Disclosure posture. Bachem has been the reference vendor in synthetic peptide chemistry for half a century; their published catalog and the methodology underlying it have influenced the way the field thinks about peptide characterization full stop. The bound paper data sheets that ship with custom synthesis orders remain the gold standard for completeness: identity, purity, peptide content, water content, counterion content, and endotoxin where applicable, with method conditions stated explicitly.

Where Bachem clears the bar. C1 (chromatograms), C3 (COA structure and method detail), C4 (stability data — particularly for their pharma-grade lines, where ICH-guideline stability programs are intrinsic to the workflow), C5 (sequence verification via MS/MS with Edman where ambiguity exists), and C6 (NMR and AAA both available, AAA standard on longer sequences) all pass without qualification.

Where Bachem fails: C2, per-batch mass spectrometry on catalog material. For custom-synthesis and pharma-grade orders, per-batch MS is performed and disclosed as part of the standard analytical package. For off-the-shelf catalog products at research grade, the published technical documentation refers to a reference MS spectrum for the SKU rather than a per-batch acquisition. This is a defensible commercial decision — the SKU-level reference is analytically equivalent for a well-characterized synthesis — but it does not satisfy the strict reading of C2 as I have defined it. A buyer who needs per-batch MS on a Bachem catalog item can request it as a documented exception; under the framework here, requiring exception handling for what should be default disclosure is the difference between 6/6 and 5/6.

Bachem remains the institutional reference for research-peptide chemistry. The single criterion miss is structural to their two-tier (catalog / custom) model, not a quality gap, and should be read as such.

Disclosure posture. GenScript built its position in the synthetic-peptide market on the custom-synthesis side. Their analytical package for custom orders is consistently complete — per-batch HPLC and per-batch MS are intrinsic to the workflow because the molecule, by definition, has not been synthesized before and a reference spectrum does not exist. C1, C2, C3 all pass on custom-synthesis material, and C5 (sequence verification, MS/MS-based) and C6 (AAA available standard, NMR on request) pass as well.

Where GenScript receives partial credit. C4 (stability and forced-degradation data) is rated partial rather than full pass. For their >90% and >95% catalog grades, stability data is referenced via shelf-life statements and storage conditions rather than published forced-degradation studies of the type that would underpin a 24-month claim. For the >98% and pharmaceutical-grade lines this is upgraded — ICH-style stability data is generated and disclosed — but on the price point most researchers buy from this vendor, C4 is light. Promoting GenScript to 6/6 requires ordering up the grade ladder. At the typical research-buying tier, AVG 5/6.

Disclosure posture. AnaSpec publishes a large research-peptide catalog with consistent SKU-level technical documentation. Their per-batch MS (C2) and sequence verification methodology (C5) are documented in the technical package that ships with the material, and these pass cleanly. Beyond those two criteria the analytical disclosure posture thins out.

Partial credits and fails. C1 (HPLC chromatogram) is rated partial — purity values are stated to ≥95% on most catalog grades and individual batch chromatograms are available on request, but they are not published as a routine matter and a representative chromatogram per SKU stands in. C3 (per-batch COA) is similarly partial — the documentation is keyed to the SKU rather than to the individual batch in many cases, and the method-level detail varies in completeness across the catalog. C4 (stability data) is not published in a form that satisfies the criterion at the catalog tier. C6 (orthogonal identification beyond HPLC and MS) is not standard at catalog grade; AAA and NMR are available as custom-order add-ons. The product is generally good; the documentation discipline is not at the level of the top three vendors here.

Disclosure posture. Pinnacle Peptides operates in the direct-to-researcher market segment with a public-facing catalog and pricing structure aimed at individual buyers rather than institutional procurement. The published analytical documentation does not satisfy any of the six criteria at the disclosure level as defined here — purity claims are presented as headline numbers without per-batch chromatograms, mass-spec validation is asserted rather than published, COAs when available are SKU-level rather than batch-level, no stability program is disclosed in technical form, sequence-verification methodology is not stated, and no orthogonal identification method is referenced.

The absence of disclosure is not equivalent to the absence of underlying analytical work — it is possible that the material is well-characterized internally and simply not published — but under the framework here, what cannot be verified cannot be scored. A 0/6 reading is a comment on the published record, not a finding about the molecule. Researchers requiring reagent-grade material with a documentary chain back to the synthesis should source elsewhere or insist on the documentation before procurement.