Research Reference · 2026 Edition

A structured reference for choosing the right peptide format.

Peptide Format Guide is a non-sponsored research reference covering vial, pen, capsule, blend, and kit formats across three peptide categories. We evaluate vendors on documentation depth, format diversity, and analytical panel scope — not affiliate incentives.

3 · Active Guides 24 · Vendors Reviewed 5-Test · Analytical Panel 0 · Sponsored Placements

Reference Guides

/ Category Index

Metabolic · GLP-1

Best Sources for GLP-1 Research Peptides in 2026

Semaglutide, Tirzepatide, and Retatrutide vendors compared across vial, pen, and kit formats. Eight US-accessible suppliers ranked by GLP-1 lineup depth and documentation.

Read the guide Recovery · Tissue Repair

Best Recovery Peptide Vendors in 2026

BPC-157, TB-500, and GHK-Cu sourced across recovery-themed kits, vials, and pens. Eight vendors evaluated on curated stack availability and per-batch CoA traceability.

Read the guide Cognition · Longevity

Best Cognition & Longevity Peptide Vendors in 2026

Semax, Selank, Epithalon, NAD+, MOTS-C and adjacent compounds compared across themed kits, pre-filled pens, and individual vial formats from eight US-accessible vendors.

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/ About

A research reference, not a storefront.

Peptide Format Guide is maintained by Dr. Marcus Whitfield, PhD (peptide biochemistry) with contributions from Devon Reyes. We consolidate vendor information across GLP-1, recovery, and cognition/longevity categories into a single research reference. We do not accept sponsored placements; all evaluations rely on publicly available documentation.

About the guide →

/ Methodology

Scoring framework & format hierarchy.

Vendor scores weight catalog breadth (25%), documentation (25%), format diversity (20%), shipping (15%), payment options (10%), and customer signals (5%). The analytical bar is a five-test panel: HPLC, mass spec, LAL, sterility, ICP-MS. No vendor scores 10/10 — the ceiling is 9.9.

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