How to Read a Certificate of Analysis

If you are buying peptides and you have not seen a Certificate of Analysis, you have no idea what is actually in the vial.

That might sound blunt, but it is the reality of the research peptide market. Without independent third-party testing, any claims a supplier makes about purity and potency are just words. A Certificate of Analysis (COA) is the document that separates a trustworthy supplier from one you should avoid.

This guide explains what a COA is, what it should contain and how to read one correctly.

What Is a Certificate of Analysis?

A Certificate of Analysis is a document from an accredited, independent laboratory that confirms the results of testing performed on a specific batch of a compound. It provides objective, verifiable data about the quality and composition of the peptide.

The key word is "independent." A COA is only meaningful if it comes from a third-party laboratory that has no financial relationship with the supplier. Internal testing documents produced by the manufacturer themselves are not the same thing and carry far less weight.

Why Does This Matter?

The research peptide market is largely unregulated. There are no mandatory quality standards enforced by a regulatory body for compounds sold as research chemicals. This means that without testing, you genuinely do not know:

• Whether the compound is what it says it is
• What purity level it has reached
• Whether it is contaminated with solvents, heavy metals or other impurities
• Whether the concentration matches what the label claims

A high-quality COA addresses all of these concerns with data.

What Should a COA Contain?

A legitimate Certificate of Analysis for a research peptide should include the following:

1. Identity Confirmation
The test should confirm that the compound is what it claims to be. Common methods include High-Performance Liquid Chromatography (HPLC) and Mass Spectrometry (MS). These techniques compare the molecular fingerprint of the sample against a reference standard.

Look for: A confirmation statement that the compound's identity matches the reference standard.

2. Purity Percentage
This is the most important figure. Purity is expressed as a percentage and reflects how much of the sample is the actual target compound versus other substances.

Look for: A purity of 98% or higher. Some premium compounds may be tested at 99% or above. Anything significantly below 98% should raise questions.

3. Testing Method
The COA should clearly state the analytical method used. HPLC (specifically Reversed-Phase HPLC) is the gold standard for peptide purity testing. Mass Spectrometry is used to confirm molecular identity.

Look for: HPLC purity data and MS identity confirmation. If the testing method is not specified, that is a red flag.

4. Batch or Lot Number
The COA should reference a specific batch number that matches the batch you are purchasing. This is how you confirm the test was run on your actual product, not some other batch.

Look for: A batch/lot number on both the COA and your product label. If they do not match, ask why.

5. Testing Date
The date of testing matters. Older results from a previous batch are not a guarantee of the quality of a current batch.

Look for: A test date that is reasonably recent and corresponds to the batch you are purchasing.

6. Laboratory Name and Accreditation
The issuing laboratory should be clearly identified. Reputable labs will also hold accreditation such as ISO/IEC 17025, which is the international standard for testing laboratories.

Look for: The lab name, location and any accreditation details. You should be able to independently verify the lab exists.

7. Heavy Metals and Solvent Residue Testing (Optional but Valuable)
Higher-quality COAs will also include results for heavy metal contamination (lead, arsenic, mercury, cadmium) and residual solvents from the manufacturing process. This level of testing reflects a more thorough quality control approach.

Red Flags to Watch For

No COA available at all
Any supplier that cannot or will not provide a COA should be avoided entirely. There is no legitimate reason for a quality supplier to withhold this information.

COA provided by the manufacturer rather than a third party
Internal testing by the same company producing the compound is not independent verification. It is not meaningless, but it is not sufficient on its own.

Purity below 98%
This indicates either a poorly manufactured product or an older batch that has degraded. For research purposes, sub-98% purity is not acceptable.

No batch number or a batch number that does not match your product
This suggests the COA may not actually correspond to the product you are buying.

Vague or unspecified testing methods
Legitimate COAs specify exactly how testing was conducted. "Tested for purity" without any further detail is not meaningful.

Lab name cannot be verified
If you search for the testing laboratory online and cannot find evidence that it exists or operates, treat that COA as unreliable.

How to Verify a COA

Beyond reading the document itself, you can take additional steps to verify its legitimacy:

1. 1.Search for the laboratory online and confirm it exists and offers analytical testing services
2. 2.Check whether the lab holds any recognised accreditation
3. 3.If in doubt, contact the supplier and ask direct questions about the testing process
4. 4.Compare the batch number on the COA to the label or documentation provided with your order

Reputable suppliers welcome these questions. Suppliers who are evasive or dismissive about COA verification are telling you something important.

What STRIATA Does

All STRIATA peptides are accompanied by third-party Certificates of Analysis from accredited independent laboratories. We test for identity, purity (using HPLC) and, where applicable, solvent residues and heavy metals. Our COAs are available on request for every product we carry.

We believe this is the minimum standard for operating responsibly in this space, not a differentiator. If your current supplier is not providing this level of documentation, it is worth asking why.

Disclaimer: The information in this article is for educational purposes only. STRIATA peptides are sold as research compounds. Always source from verified, tested suppliers and consult a qualified healthcare professional before beginning any protocol.