A COA is only valuable if you know what it says — and what it doesn't. This guide explains every field a legitimate peptide COA should contain, and what to look for when something is missing or suspicious.
A Certificate of Analysis is a document issued by a testing laboratory confirming that a specific batch of material has been tested against defined quality specifications. For research peptides, it is the primary evidence that what you received matches what was described.
A peptide COA should contain, at minimum: the product name and sequence, the lot/batch number, the HPLC purity percentage, a mass spectrometry molecular weight result, the name of the testing laboratory, and the date of testing. Any COA missing these elements should be treated with skepticism.
The importance of COA verification cannot be overstated in preclinical research. A peptide with 85% purity contains 15% of unknown material — residual synthesis reagents, deletion sequences, oxidized variants, or unrelated compounds. Experimental results using impure material may be unreproducible and are unreliable for drawing mechanistic conclusions.
Find the lot or batch number printed on your vial label. Cross-reference it with the batch number on the COA. They must be identical. If a supplier provides a generic COA without a specific lot number, or provides a single COA for all inventory of a product, the document does not verify your specific material.
This is the most important single number on the COA. ≥98% is research-grade; ≥99% is high-purity. The HPLC result tells you what percentage of the measured sample is the target peptide. Anything below 95% introduces significant unknown material into your experimental system.
The MS result confirms the compound's molecular weight matches the theoretical weight for the peptide sequence. HPLC only measures relative peak proportions — it does not tell you whether the dominant peak is actually your target peptide. Mass spec closes that gap. For BPC-157: expected MW is 1419.53 Da.
Is the COA from an independent third-party lab, or from the supplier's own internal testing? Third-party COAs are issued by labs with no financial interest in the result. Internal COAs represent self-certification. Both can be legitimate, but third-party testing carries more evidentiary weight for research documentation.
A COA from 3 years ago may not reflect the current state of a product. Peptides stored improperly degrade over time. COA dates should be reasonably recent, and suppliers should be retesting inventory rather than relying on historical batch results indefinitely.
HPLC stands for High-Performance Liquid Chromatography. The technique works by flowing a dissolved sample through a column packed with materials that interact differently with different compounds. The target peptide travels through at a predictable rate; impurities travel at different rates. A detector measures how much material passes through at each point in time, creating a chromatogram — a graph of peaks.
The "purity" percentage is the area under your target peptide peak expressed as a fraction of the total peak area. A result of 99.2% means that 99.2% of the measurable material in the sample elutes at the expected time for your peptide. The remaining 0.8% could be degradation products, synthesis byproducts, or other impurities.
HPLC purity cannot confirm the identity of the dominant peak. A sample could be 99% pure of a completely wrong compound and pass an HPLC purity check. That is why mass spectrometry confirmation is required alongside HPLC — the two tests together confirm both identity and purity.
Peer-reviewed BPC-157 studies typically report the purity of the compound used. This matters for replication: if a study used 98% pure material and you replicate with 90% pure material, any differences in results could reflect impurity content rather than peptide dose. Matching or exceeding the source purity is part of sound protocol design.
Not all COAs represent legitimate quality documentation. The following are common indicators that a COA should be questioned before relying on it for research:
Using material with unverified or insufficient COA documentation in published research creates methodological problems. Most legitimate journals require disclosure of compound source and purity characterization. Invest in proper source verification before experimental work begins, not after.
Enter your batch number to pull the full third-party test results for your specific vial.
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