Last month's FDA advisory panel vote on peptide compounding made headlines everywhere — but it's created almost as much confusion as clarity. Here's what actually changed, what hasn't, and what to expect next.
5 Red Flags to Watch For When Choosing a Research Peptide Supplier
With regulatory attention on peptide purity and sourcing higher than ever, knowing how to evaluate a supplier yourself is one of the most useful skills a researcher can have. Here are five warning signs that should make you think twice before ordering.
Red Flag #1: No Certificate of Analysis (COA), or "Available on Request"
A legitimate supplier provides a batch-specific Certificate of Analysis with every order, showing identity and purity confirmed by third-party testing — not a generic PDF, and not something you have to ask for after the fact.
Red Flag #2: Prices That Are Dramatically Below Market Rate
Third-party HPLC/MS testing, proper synthesis, and cold-chain handling all cost money. Prices far below the norm are a strong signal that one or more of those steps has been skipped.
Red Flag #3: No Batch or Lot Numbers on the Product
Without a lot number, there's no way to trace a vial back to its testing documentation — meaning any COA the supplier does provide can't actually be verified against what you received.
Red Flag #4: Vague or Missing Testing Methodology
"Tested for purity" means nothing without specifics. Legitimate suppliers name the method (HPLC, mass spec), the lab, and the standard they're testing against.
Red Flag #5: No Transparency About Sourcing or Manufacturing
Suppliers unwilling to say where or how a peptide is made are usually hiding something — whether that's an unreliable manufacturing partner or inconsistent quality control between batches.
A Note on This Guide
These red flags reflect general best practices used across the research chemical and dietary supplement industries for evaluating supplier transparency, including standards commonly cited by third-party testing labs and quality-assurance organizations. This guide is provided for general educational purposes and is not a guarantee about any specific supplier.

