How to Read a Certificate of Analysis

A Certificate of Analysis (COA) is a document from a third-party testing laboratory that confirms what's actually in a compound vial. In the research peptide space, where quality control from vendors varies enormously, the COA is the primary tool researchers have for verifying that a compound is what it's claimed to be, at the purity level it's claimed to have.

Knowing how to read one takes five minutes. Not knowing how to read one means you're trusting a label instead of data.

What a COA Contains

A legitimate COA from a reputable testing lab includes several standard components. The exact format varies by laboratory, but the core data is consistent.

Sample identification: The compound name, batch or lot number, and sometimes the submitting vendor's information. This links the test to a specific production batch, not just a compound in general.

Testing date: When the analysis was run. A COA from three years ago on a compound sold today is not meaningful verification of the current batch. Fresh COAs, matched to the batch you're receiving, are what actually matter.

Test methods used: The two methods you want to see are HPLC and mass spectrometry. If only one is present, that's worth noting. If neither is present, the COA is not providing useful verification.

Results: Purity percentage, and in the case of mass spec, the observed mass versus the theoretical mass. These are the numbers you're reading.

HPLC: Purity by Area

High-performance liquid chromatography (HPLC) separates the components of a sample by passing them through a column at high pressure. Different compounds travel through the column at different rates and emerge as distinct peaks on a chromatogram. The size of each peak, measured by area, corresponds to the relative quantity of that component in the sample.

Purity by HPLC is calculated as the area of the target compound's peak divided by the total area of all peaks, expressed as a percentage. A result of 99.2% purity means 99.2% of the detected material is the target compound. The remaining 0.8% is other compounds, typically synthesis byproducts or degradation products.

What HPLC tells you: how pure the compound is. What it doesn't tell you on its own: whether the compound is the right compound. A 99% pure sample of the wrong peptide would show 99% purity by HPLC. That's where mass spectrometry comes in.

Mass Spectrometry: Identity Confirmation

Mass spectrometry (MS) identifies compounds by measuring their molecular mass and fragmentation pattern. Every molecule has a characteristic mass. If you know the theoretical molecular weight of the peptide you ordered, and mass spec shows an observed mass that matches within acceptable tolerance (typically within 1-2 Da), you can confirm the compound is what it's claimed to be.

The combination of HPLC and MS gives you both identity and purity. HPLC confirms the sample is predominantly one compound. MS confirms that compound is the right one. Together, they're the standard for research-grade verification.

Some labs also run related substance analysis as part of the HPLC test, identifying specific known impurities or degradation products by name rather than just reporting them as "other." This level of detail is useful for research protocols where specific impurities could confound results.

Understanding the Janoshik Report

Lumé uses Janoshik Analytical, a Czech-based testing laboratory that has become the most widely referenced third-party tester in the research peptide space. Janoshik reports are publicly searchable on their website (janoshik.com), which means you can verify a COA's legitimacy independently without taking anyone's word for it.

A Janoshik report includes the order number, test date, compound name, HPLC purity result, and mass spectrometry data. The public search function lets you enter the order number from any COA and pull up the actual lab record. If the COA a vendor provides matches the Janoshik database entry, the document is verified. If the order number doesn't exist in the database, or the results don't match, that's a red flag.

This verification step takes 30 seconds and should be standard practice before beginning any research protocol with a new batch.

Red Flags on a COA

Not every COA is equally meaningful. These are signs that a document provides limited or no real verification:

• No third-party lab: A COA issued by the manufacturer's own internal lab is not independent verification. It's the vendor testing their own product. Third-party means an external lab with no financial relationship to the vendor.
• No mass spectrometry: HPLC alone confirms purity but not identity. A COA without MS cannot confirm the compound is what it claims to be.
• No batch or lot number: Without a batch number, the COA can't be matched to the specific product you received. It could be recycled across different batches or compounds.
• Old testing dates: Peptides degrade over time, and synthesis processes can change. A COA from years ago doesn't reflect the current product.
• Purity below 98%: Research-grade compounds should test at 98% minimum, with 99%+ being the standard for premium sourcing. Anything below 95% is not research-grade by any reasonable standard.
• No public verifiability: If the COA can't be independently verified through the lab's public database, you're relying on a document that could be fabricated.

How to Use the Lumé COA Page

Lumé's COA page lists all 18 compounds by category with Janoshik links for each batch. You can pull the order number directly from the linked report and verify it in the Janoshik database. If you have questions about a specific batch or need COA documentation for your research records, contact support@lumepeptides.com.

The COA is the only objective data point between a vendor's claim and your research results. Reading it correctly takes minutes. Skipping it is a choice to base your work on trust instead of evidence.