Buyer’s guide · Certificate of Analysis
How to read a peptide Certificate of Analysis
Last updated: 27 August 2026
A Certificate of Analysis — a COA — is a laboratory document stating what a batch actually contains. It’s the only meaningful evidence a buyer has that a product is what the label says.
Without one, you’re trusting a printed label. Anyone can print a label.
Here’s how to read one properly.
Definition
What a COA is
A COA is produced by an analytical laboratory after testing a physical sample from a specific batch. It reports what the lab found: how pure the sample was, whether the molecule was the one claimed, and often how much of it was present.
A COA is tied to one batch. It is not a general certificate for a product line, and it is not a licence or an approval.
The essentials
The three things that matter
1. Purity — measured by HPLC
HPLC stands for High-Performance Liquid Chromatography. The sample is dissolved and pushed through a column that separates its components. Each component appears as a peak on a chromatogram, and the size of each peak indicates how much of the total that component represents.
The main peak is the peptide. Everything else is impurity — fragments, by-products, residual reagents.
The benchmark to look for is 98% or higher. Research-grade peptides are commonly reported at 98–99%+.
Look at the chromatogram itself if it’s included, not just the number. A clean trace shows one dominant peak. Lots of small peaks around it means a messier synthesis.
2. Identity — confirmed by mass spectrometry
Purity tells you the sample is mostly one thing. It doesn’t tell you that thing is what you ordered.
Mass spectrometry answers that. It measures the molecular weight of the compound and compares it against the expected weight for that peptide sequence. If they match, the identity is confirmed.
A COA with purity but no identity testing is only telling you half the story. A sample can be 99% pure and still be 99% of the wrong molecule.
3. Who did the testing
This is the one most people skip, and it’s the most important.
A test commissioned and reported by the seller is not independent. The laboratory should be a third party with no commercial interest in the result, and the COA should name it.
Well-known independent laboratories in this space include Janoshik Analytical, which is widely used across the research peptide industry.
If a seller says “third-party tested” but the COA carries no laboratory name, that claim is unverifiable.
Also worth checking
Beyond the headline numbers
- Batch number. Does the COA reference a specific batch, and does that batch match what you’re being sold? A COA for a different batch tells you about a different batch.
- Test date. A COA from years ago tells you about a batch that no longer exists.
- Quantity. Some COAs report the actual measured mass. Useful, because a vial labelled 10mg that contains 7mg is a problem that purity testing alone won’t reveal.
- Sample source. The strongest COAs state that the lab received the sample independently rather than being sent a hand-picked one.
Red flags
How to spot a weak or fake COA
- No laboratory name on the document.
- No batch number, or a batch number that doesn’t match the product.
- An image rather than a document — a screenshot with no chromatogram.
- Purity claimed but no chromatogram shown.
- The same COA used across multiple products or batches.
- Round numbers only — real analytical results are rarely exactly “99%”.
- No identity testing, only purity.
If there isn’t one
Walk away
In a market of unregulated products, a published, independent, batch-specific COA is the single clearest line between sellers who can prove what they’re selling and sellers who can’t. If it isn’t published, there’s usually a reason.
What we do
Every batch, every certificate, published
Every Optigenix batch is tested by an independent third-party laboratory, and the Certificate of Analysis is published openly in our COA Library with the batch number.
You can read it before you buy, not after.
Research use only. Optigenix Health supplies research compounds strictly for laboratory research purposes. Not for human consumption. Not intended to diagnose, treat, cure or prevent any disease. Purchasers must be 18 or over.