PRODUCTS SOLD ON PEPTIDESLABIRELAND.COM ARE FOR RESEARCH PURPOSES ONLY AND ARE NOT FOR HUMAN OR VETERINARY USE.
Fast Ireland delivery — dispatched to Dublin, Cork, Galway, Limerick and nationwide.
PRODUCTS SOLD ON PEPTIDESLABIRELAND.COM ARE FOR RESEARCH PURPOSES ONLY AND ARE NOT FOR HUMAN OR VETERINARY USE.
Fast Ireland delivery — dispatched to Dublin, Cork, Galway, Limerick and nationwide.
By the Peptides Lab Ireland research team · Updated July 2026
A Certificate of Analysis , or COA — is the single most important document you receive with a research peptide. It’s the supplier’s evidence for every claim they make about purity, identity, water content and endotoxin. If you can’t read a COA, you can’t independently verify your reagent. This guide walks through the fields Irish research groups should always check.
A COA is a lot-specific analytical report generated by a laboratory that tests a peptide batch and documents its measurable properties. Legitimate research peptide suppliers issue COAs on a per-batch basis , each production lot has its own COA, keyed to a batch or lot number that also appears on the vial you receive.
A COA is not:
If you can’t see a lab name, a method, and a lot number linking the COA to the physical vial in your hand, it isn’t functioning as a COA.
Full peptide name, molecular formula and molecular weight. The molecular weight in your COA should match the reference weight for the compound (e.g., BPC-157 ≈ 1419.5 Da, GHK-Cu ≈ 402.9 Da, Semaglutide ≈ 4113.6 Da). A significant mismatch means the compound isn’t what the label says.
Every COA is tied to a specific batch. If your vial says “Batch B24-047” and the COA says “Batch B24-051” and those don’t match. Different batch, different data.
When was the peptide produced? When was it tested? Peptides degrade , with a COA from three years ago on a vial you just received isn’t evidence of current quality.
The gold standard purity measurement. Look for:
A COA that gives “purity: 99%” with no method, no wavelength and no chromatogram is a marketing claim, not analytical evidence.
Mass spec confirms the compound’s identity by measuring its molecular weight independently of HPLC. The observed mass should match the theoretical mass within a small error window (typically < 1 Da for peptides of this size). ESI-MS or MALDI-TOF are the two common methods.
Lyophilised peptides contain some residual water. Water content above 5–8% affects both stability and your dosing calculations. A proper COA reports water content measured by Karl Fischer titration.
For peptides being used in cell culture or animal-model research, endotoxin levels matter , with LPS contamination can invalidate immune-biology and inflammation research. Endotoxin is reported in Endotoxin Units per mg (EU/mg). Research-grade material should show < 5 EU/mg; anything for sensitive protocols should be lower.
The COA should specify storage temperature (typically −20 °C for lyophilised) and reference stability data. This tells you the window in which the reported values remain valid.
The following should stop you from proceeding with a research protocol:
Every batch we supply is independently tested by Optima Labs. Each COA includes:
Batch numbers on the COA match the vial label. If they don’t, contact us and we treat this as a serious traceability issue.
For Irish research groups building peptide QC procedures into standard operating protocols, we recommend:
All compounds supplied by Peptides Lab Ireland are for in-vitro laboratory research and educational use only. Not intended for human or veterinary use.
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