How we evaluate peptide vendors

This page documents the framework used across every guide on Peptide Format Guide. Every vendor in every ranking is scored against the same criteria, and the same weighting is applied across the three peptide categories we currently cover.

The format hierarchy we evaluate

Most peptide vendors describe their catalog in terms of compounds: "We stock BPC-157, TB-500, Semaglutide." That framing under-reports a critical research variable — the format the compound ships in. The same active ingredient behaves very differently in a research workflow depending on whether it arrives as:

• Lyophilized vial — the canonical research format; requires reconstitution.
• Pre-filled pen — calibrated-dial delivery; eliminates reconstitution arithmetic; less common.
• Capsule — relevant for oral-bioavailability research and certain stability studies.
• Blend — two or more peptides in a single vial; convenient but loses individual batch traceability.
• Kit — multiple individually documented vials grouped under a research goal.

Each guide evaluates which formats a vendor offers for the compound class under review. A vendor that stocks BPC-157 only as a vial is scored differently from one that stocks it as a vial, pen, capsule, blend component, and kit member.

What "format diversity" means for research workflows

Format diversity matters operationally. A pen format reduces reconstitution variability and enables tighter dose-response work. A kit format reduces procurement overhead for multi-compound protocols. A blend reduces the number of vials handled but eliminates per-compound batch verification. Capsules support oral bioavailability research designs that vials cannot. Researchers who can choose the right format reduce protocol noise; researchers stuck with one format must engineer around it.

The five-test analytical panel

For documentation depth, we evaluate vendors against a five-test analytical panel:

• HPLC purity — the baseline measurement; we expect ≥99% for premium catalogs.
• Mass spectrometry — confirms compound identity, not just purity.
• LAL endotoxin — detects bacterial endotoxin contamination relevant for any in-solution work.
• Sterility — microbial growth assessment.
• ICP-MS heavy metals — trace metal contamination panel.

Vendors that publish all five tests on every batch earn the highest documentation score. Vendors that publish only HPLC are scored substantially lower regardless of stated purity numbers.

Score calculation

Every vendor in every guide is scored out of 10 using the following weighted criteria:

• Catalog breadth (25%) — how many compounds the vendor stocks relevant to the guide category, and total SKU count.
• Documentation (25%) — analytical panel scope, CoA accessibility, batch-to-vial traceability (QR code or equivalent).
• Format diversity (20%) — number of formats offered for the category's primary compounds.
• Shipping & logistics (15%) — domestic shipping speed, cutoff times, ambient stability, fulfillment reliability.
• Payment options (10%) — card, cryptocurrency, wire, check, B2B terms.
• Customer signals (5%) — Trustpilot, on-site reviews, community feedback where verifiable.

Why no vendor scores 10/10

The scoring ceiling is 9.9. No vendor reaches 10 because no peptide vendor on the public market currently combines every theoretical maximum across all six criteria — perfect documentation, every format, every payment rail, instant shipping, and unanimously positive customer signal. The 9.9 cap is a deliberate honesty correction: a 10/10 implies a verified perfect score across criteria that include criteria-by-design partially subjective signals.

Sources we use

Vendor evaluations rely on three source classes:

• Primary — vendor websites (catalog, CoA libraries, terms, FAQ), Lab Hub-style batch portals, and direct vendor documentation.
• Secondary — public third-party testing archives (Janoshik, Finnrick, etc.), Trustpilot, Peptide Critic threads, and community discussion forums where verifiable.
• Tertiary — peer-reviewed literature for peptide mechanism-of-action references and historical pricing data from PeptiPrices.

Update cadence

Guides are updated as the catalog landscape changes. Major catalog changes (new SKUs, discontinued formats, kit reformulations) trigger a re-score. Pricing snapshots are refreshed quarterly. The "Updated" date at the top of every guide reflects the most recent score-relevant review.

Compliance disclaimer

All peptides referenced on this site are for laboratory research only and are not approved for human consumption or therapeutic use in any jurisdiction. Peptide Format Guide does not sell, distribute, or facilitate the sale of any peptide compound; the site is an informational research reference only.