Chromatographic Purity vs Measured Content

Two numbers often appear on peptide certificates: chromatographic purity and measured content (assay versus label claim). They answer different analytical questions. This page uses only PureLab’s two published lot examples. It is not a dosing guide and not a claim about untested catalog items.

What chromatographic purity means

Under a stated HPLC method, chromatographic purity is typically the percentage of the main peak area relative to other observed peaks. A high purity figure means the chromatogram is dominated by the main analyte peak — it does not by itself prove how many milligrams of peptide are in the vial.

What measured content means

Measured content compares the laboratory’s recovered mass to the manufacturer’s labeled mass. Results are often written as “X mg of Y mg label” and as a percentage of label claim.

PureLab example 1 — Retatrutide lot fghe8m6

• Laboratory: Krause Analytical, Austin TX
• Report date: August 5, 2026
• Method: HPLC-UV-MS
• Chromatographic purity: >99.9%
• Measured content: 26.3 mg of 30 mg label claim (87.6%)

Certificates: lot page · Retatrutide hub · product Retatrutide.

PureLab example 2 — BPC-157 lot 8sprqvs

• Laboratory: Krause Analytical, Austin TX
• Report date: July 23, 2026
• Method: HPLC-UV-MS
• Chromatographic purity: >99.1%
• Measured content: 9.47 mg of 10 mg label claim (94.7%)

Certificates: lot page · BPC-157 hub · product BPC-157.

Why both numbers matter

Lot fghe8m6 shows that a chromatogram can read >99.9% pure while recovered mass is 87.6% of the 30 mg label. Lot 8sprqvs shows >99.1% purity with 94.7% of a 10 mg label. Neither figure replaces the other. Catalog items without published certificates must not be assumed to match these results.

Further reading: how to verify a peptide COA · Krause-specific verification · peptide purity and HPLC.