A Peptide Certificate of Analysis (CoA) is a quality report for a specific batch of peptides. It provides laboratory-verified proof that what is inside the vial matches what is on the label in terms of identity, purity, and quantity.

All peptides on this site have been lyophilized. Lyophilization is a freeze-drying process that removes water to stabilize and preserve the peptide and extend shelf life. In a vial, a lyophilized peptide looks like a small cake of powder. Peptides are often tested in a lyophilized state.

Lyophilized peptides require reconstitution to be injectable liquids.

Independent laboratories perform tests on submitted peptide batch samples and report their findings in CoAs. The CoAs are usually also published on the testing laboratory’s website for verification.

Key Components of a CoA

A standard CoA typically contains five basic pieces of information:

Product Name: The peptide that was tested.

Listed quantity: Usually expressed in milligrams(mg), the amount of peptide the manufacturer lists is contained in the vial.

Batch/Lot Number: A batch or lot number assigned by the manufacturer. There is no standard format but the number must be traceable and unique.

Purity percentage: The purity of the tested peptide.

Net Peptide Content: The amount of lyophilized content that is the peptide at the tested purity level.

Interpreting the Data

Most attention is usually focused on Purity. Ideally, look for 99% purity. The remaining percentage content will consist of trace amounts of lyophilization by-products.

Much less is made of Net Peptide Content but it is critical. High-quality peptides often test at a content greater than the listed quantity. In the CoA below, the tested vial is listed as containing 30mg of Tirzepatide but the Net Peptide Content is actually 33.25mg. A manufacturer might overfill the vial to ensure that Net Peptide Content meets or exceeds the listed quantity after lyophilization.

It oftens seems like every manufacturer claims their peptides are 99% purity but a poor-quality vial could contain a peptide of 99% purity that constitutes less than the listed quantity of the vial.

CoA Example

Based in Prague, Czech Republic, Janoshik is becoming one of the best-known testing laboratories for research peptides. In this CoA, a 30mg vial contains 33.25mg of Tirzepatide at 99.645% purity. A Unique Key at the bottom can be used to verify the CoA on Janoshik’s website. Clearly, this would be an excellent product to buy! As listed on the CoA, there would also be at least one photo of the tested vial.