Red Flags in Peptide COAs: How to Spot Unreliable Suppliers
Research Use Only. This article is for scientific and educational reference only. All products are sold for research purposes and are not intended for human or animal consumption.
# Red Flags in Peptide COAs: How to Spot Unreliable Suppliers
For Research Purposes Only — Not Intended for Human or Animal Consumption
The Certificate of Analysis (COA) is the primary quality documentation for research peptides. Not all COAs are created equal — some suppliers provide COAs that are misleading, incomplete, or fabricated.
Red Flag 1: No Third-Party Testing
The most important quality indicator is whether the COA was generated by an independent third-party laboratory. A supplier testing their own products has a financial incentive to report favorable results. The COA should clearly identify the testing laboratory by name, with verifiable contact information.
Red Flag 2: Missing Mass Spectrometry Data
A COA reporting only HPLC purity without mass spectrometry identity confirmation is incomplete. HPLC cannot confirm that the target compound is actually present — only that something elutes at the expected retention time. MS confirmation of molecular weight is essential.
Red Flag 3: Implausibly High Purity Claims
Purity claims above 99.5% for complex peptides at low prices should prompt skepticism. Very high purity requires extensive preparative HPLC purification that adds significant cost.
Red Flag 4: No Lot Number or Testing Date
Without a lot number, the COA cannot be traced to a specific batch. Without a testing date, the currency of the analysis cannot be assessed.
Red Flag 5: Generic Template COAs
If COAs from the same supplier share lot numbers, testing dates, or report numbers across different products, they may be fabricated.
What a Good COA Includes
- Product name and amino acid sequence - Theoretical and observed molecular weight (MS) - HPLC purity with chromatogram data - Lot number matching the product vial - Testing date - Third-party laboratory name, address, and contact information
References
- FDA. (2015). Guidance for Industry: Analytical Procedures and Methods Validation for Drugs and Biologics.
- ICH. (2005). Q2(R1): Validation of Analytical Procedures: Text and Methodology.