How to Read a Peptide COA

Section 1: lab and sample information

The top of a legitimate COA should clearly state:

• Issuing laboratory name — should be an independent third-party lab, not the vendor or manufacturer.
• Lab address & contact — a real, verifiable physical address; no P.O. boxes only.
• Sample name and lot number — matches the product you are evaluating.
• Date received and date tested — fresh testing; old COAs applied to new lots are a red flag.
• Client name — the company that submitted the sample for testing.

Red flag: the lab name is the same as the vendor, or no lab name or address is visible.

Section 2: HPLC purity result

The HPLC purity result is the most prominent number on a peptide COA. It represents the percentage of the total sample that is the target peptide.

• ≥ 98 % — research grade.
• 95–97 % — standard grade.
• < 95 % — below standard.

Also look at the chromatogram if it’s included. A single dominant peak with small baseline impurity peaks indicates high quality. Multiple major peaks is a serious quality issue.

Section 3: mass-spectrometry identity

The MS result should confirm that the compound matches the theoretical molecular weight of the claimed peptide. Look for:

• Observed molecular weight (m/z) vs theoretical — should match within ±0.5 Da.
• “Confirmed” or “Identity: Pass” determination.
• The specific m/z values observed and the charge states.

Red flag: no mass-spec section at all, or MS data that doesn’t include observed m/z values. A COA without MS cannot confirm the compound’s identity.

Section 4: Net Peptide Content (NPC)

NPC represents the true active peptide mass as a percentage of total sample weight. A typical research peptide might have an NPC of 75–85 %, meaning a 10 mg vial contains only 7.5–8.5 mg of actual peptide — the rest is TFA, moisture, and counter-ions.

Without NPC data, dosing from weight alone is inaccurate. This is why NPC is included in all Identity + Potency panels at Gold Standard Analytics.

Section 5: verification information

The most important trust signal on any COA is a verifiable accession number that links to the lab’s own public database.

Every COA from Gold Standard Analytics includes a unique accession number you can check at goldstandardanalytics.com/coa-lookup. If the number returns a match, the COA is genuine. If it doesn’t exist in our database, the document was not issued by us.

Red flag: no accession number or verification system. Without this, you have no way to confirm the COA was not fabricated.