Glossary
Certificate of Analysis (CoA)
A document reporting the tests run on a batch, typically HPLC purity and mass spectrometry identity. It is only meaningful if it matches your batch reference.
Relevant compounds
Further reading
- How to choose a research peptide supplier: a UK buyer's checklist
Ten checks to run before ordering research peptides: batch-matched CoAs, independent testing, transparent pricing, clear labelling and honest claims.
- HPLC vs mass spectrometry: what each test tells you about a peptide
HPLC measures purity, mass spectrometry confirms identity. Why a CoA needs both, what each cannot detect and how to read the results.
- Batch verification and traceability: proving a CoA belongs to your vial
How batch numbers, lab references and online lookups connect a Certificate of Analysis to the vial in your hands, and what to do when they do not match.
- Research peptide red flags: warning signs on supplier sites and CoAs
The patterns that separate documented suppliers from risky ones: missing batch data, perfect-looking numbers, human-use claims and pressure tactics.
- TFA vs acetate peptide salts: why the counter-ion matters
Synthetic peptides are supplied as salts. What trifluoroacetate and acetate counter-ions are, why they change net content and when the choice matters.
- Semaglutide vs tirzepatide vs retatrutide: the three incretin peptides compared
How the three best-known incretin research compounds differ in receptor targets, evidence and regulatory status, with links to each head-to-head comparison.