What is a Certificate of Analysis?
A Certificate of Analysis (COA) is a lab report that verifies the quality of a specific batch of research peptides. It confirms two critical things:
Identity
Confirms the peptide is actually what the label says it is. Verified through mass spectrometry matching the expected molecular weight.
Purity
Shows how clean the peptide is from impurities. Measured via HPLC analysis. Aim for 99% or higher for best quality.
What a COA Does NOT Tell You
A COA checks a sample for purity and identity, but it doesn't guarantee:
- •The actual amount of peptide in your vial (fill accuracy)
- •Whether the vial is properly filled or underfilled
- •Sterility of the final product
- •Safety for any specific use
Underfill vs. Overfill
Underfill
The vial has less peptide than labeled — like getting only 7mg in a "10mg" vial. This is a common issue and hard to spot without weighing the powder yourself.
Overfill
When there's a bit extra (like 11-12mg), which good manufacturers do on purpose to make up for small losses during production.
Even with a great COA showing high purity, underfill can mean you're getting less active peptide than you paid for. Some COAs include "Net Peptide Content" which shows the actual amount.
Overfill / Underfill Calculator
Enter the labeled amount on the vial and the actual tested amount from the COA to see if your peptide is overfilled or underfilled.