A peptide COA uses a small set of abbreviations: HPLC-RTM and HPLC-DAD are identity tests by HPLC, NMT means “not more than”, NLT means “not less than”, EU/mL is the unit for bacterial endotoxin, ICP-MS is the heavy-metals method, and “Report Only” means a value with no pass or fail limit. This glossary defines each term in one or two sentences and shows where it appears on a real certificate: every example below is taken from a Clean Peptide certificate from ILS Laboratories, HYTE Research Division, Accurate Test Labs or Nexus Scientific, and links to its lot page.
For a step-by-step walk through a whole certificate, see how to read a peptide COA. This page is the reference to keep open beside it.
Purity and identity
HPLC
High-performance liquid chromatography: the sample is pumped through a column, its components leave the column at different times, and a detector records each one as a peak. Peptide certificates use it for purity, identity and content. Example: every one of our certificates for lyophilised peptides reports an HPLC purity, such as 99.56% for BPC-157 10 mg, lot ACE-1090357.
HPLC purity (peptide purity, peak area purity)
The share of the target peptide’s peak among the peptide-related peaks the detector sees, as a percentage. ILS Laboratories’ notes describe it as “RP-HPLC area normalization at 214 nm”, with non-peptide impurities excluded from the calculation. HYTE Research Division calls the same kind of result “peak area purity”. Purity says nothing about how many milligrams are in the vial.
RP-HPLC and 214 nm
RP-HPLC is reversed-phase HPLC, the usual mode for peptides. 214 nm is an ultraviolet wavelength at which the peptide bond absorbs strongly, so peptide-related peaks show up there. Example: the chromatograms on our ILS certificates for BPC-157 10 mg and TB-500 10 mg are titled “UV 214nm”; the Accurate Test Labs chromatogram for BPC-157 20 mg is recorded at 220 nm.
Chromatogram and retention time
The chromatogram is the trace of detector signal against time. Retention time is the minute at which a peak comes off the column. Example: on the BPC-157 20 mg certificate from Accurate Test Labs, the main peak is labelled “11.461 / BPC-157”, meaning BPC-157 eluted at 11.461 minutes.
HPLC-RTM
ILS Laboratories’ identity test by HPLC retention time. Its certificates describe it as “identification by chromatographic retention time comparison with a reference standard”: the sample’s main peak has to appear at the same time as the standard’s. Example: “Identity (HPLC-RTM) TB-500, Confirmed” on TB-500 10 mg, lot ACE-7203111. It is not mass spectrometry.
HPLC-DAD (and PDA)
HPLC with a diode-array detector, which records ultraviolet absorbance across a range of wavelengths at once, so a peak can be compared with a reference standard’s peak. PDA (photodiode array) is another name for the same kind of detector. Example: “Identity, HPLC-DAD, KPV confirmed” on KPV 10 mg, lot 202608KPV10, from HYTE Research Division.
Reference standard
A sample of the compound with a known identity (and, for content assays, a known content) that the laboratory runs alongside the test sample. Identity by HPLC is only as specific as the reference it is compared with.
Mass spectrometry (MS)
A method that measures the mass of the molecule itself, so it can confirm a peptide’s molecular weight. None of our current certificates reports a mass spectrometry result for the peptide; their identity tests are by HPLC retention time or HPLC-DAD. (ICP-MS, below, is mass spectrometry of elements, not of the peptide.)
How much is in the vial
Labeled content (label claim)
The nominal amount the vial is sold as, printed on the certificate so the result can be compared with it. Example: “Labeled Content: 10mg” on our ILS certificates; “NLT 90% of label claim” in HYTE specifications.
Net peptide content
The milligrams of the peptide itself that the laboratory measured in the tested vial, meant to exclude water and counter-ions such as acetate. It is a different number from purity. Example: 10.31 mg in TB-500 10 mg. Our guide to content above the label compares it with the label for 27 lots.
Net blend peptide content
The same measurement for a blend, given as a total and per component. Example: “10.49mg (BPC-157 5.25mg + TB-500 5.25mg)” on BPC-157 / TB-500 Blend 10 mg.
Quantity, net quantity and curve assay
HYTE Research Division’s names for the content result. “Curve assay” means the amount is read off a calibration curve built from a reference standard. Example: “Quantity, Curve Assay, 12.94mg” for KPV; “0.98mg/mL” for Adamax Spray, where the result is a concentration.
mg/unit and mg/mL
Units for content. mg/unit is milligrams per vial, used by Accurate Test Labs: “20.99 mg/unit” for BPC-157 20 mg. mg/mL is milligrams per millilitre, used for solutions such as our sprays.
The safety panel
Endotoxin and EU/mL
Bacterial endotoxins are fragments of the outer membrane of Gram-negative bacteria. They are measured in endotoxin units per millilitre (EU/mL). Example: 0.134 EU/mL for BPC-157 10 mg; 0.50 EU/mL for bacteriostatic water, lot BAC-0023530.
USP <85>
The United States Pharmacopeia’s chapter on the bacterial endotoxins test. ILS Laboratories states that its endotoxin result is “tested per USP <85> kinetic chromogenic method”, with acceptance criteria per client specification.
LAL (chromogenic, ELISA)
Limulus amebocyte lysate, the reagent behind the standard endotoxin tests; “chromogenic” means the result is read as a colour change. HYTE Research Division lists its endotoxin method as “LAL Chromogenic” on the KPV certificate and “LAL ELISA” on the GLP-2 Tirz 20 mg certificate.
Sterility (PCR, pour plate) and “No Growth”
A test for living micro-organisms in the sample. ILS Laboratories lists its sterility method as PCR; HYTE Research Division uses pour plate, a culture method in which the sample is set in agar and incubated. “No Growth” is the passing result on both. Sterility is a separate test from endotoxin.
Heavy metals and ICP-MS
Heavy metals is a screen for toxic elements. ICP-MS (inductively coupled plasma mass spectrometry) is the method ILS Laboratories uses, “per USP <233> methodology”, for arsenic, cadmium, lead, mercury and chromium. Its notes say the limits are internal screening limits, not a pharmacopoeial monograph. HYTE Research Division lists a chromogenic heavy-metals method on the KPV certificate.
ppm
Parts per million. Example: ILS’s heavy-metals limits are “NMT 1.5 ppm” for arsenic and mercury, “NMT 0.5 ppm” for cadmium, “NMT 1.0 ppm” for lead and “NMT 10.0 ppm” for chromium.
Fentanyl screen
A test for fentanyl contamination. On our ILS certificates it is an immunoassay with a 50 ng/mL cutoff, so “Not Detected” means below that cutoff. Example: Thymosin Alpha-1 10 mg, lot ACE-9487640.
Specifications and results
Specification
The limit or expected value a result is judged against. Example: “>= 95.0%” for HPLC purity on ILS certificates; “> 99.0%” on the HYTE KPV certificate.
NMT
Not more than: an upper limit. Example: “NMT 1.5 ppm” for arsenic. When a result itself is written “NMT 0.05 EU/mL”, as for GHK-Cu 50 mg, the laboratory is reporting that the value was not more than 0.05 EU/mL, without an exact figure below it.
NLT
Not less than: a lower limit, with no upper limit unless one is stated. Example: “NLT 90% of label claim” for spray concentration; “NLT 98.0%” for the purity of Selank Spray.
Report Only, Report Result and “Reported”
The laboratory gives the value without a pass or fail limit. ILS Laboratories writes “Report Only” for net peptide content (status “N/A”) and “Report Result” for endotoxin (status “Reported”).
Pass and overall disposition
Pass means the result met its specification. “Overall disposition” (HYTE Research Division) or an overall Pass at the top of the certificate (ILS Laboratories) is the laboratory’s verdict on the sample as a whole.
ND, NT, LOD and LOQ
Abbreviations defined on Accurate Test Labs certificates: ND is not detected, NT is not tested, LOD is the limit of detection (the smallest amount the method can detect) and LOQ is the limit of quantification (the smallest amount it can measure as a number).
The certificate header
Lot number (batch)
The code for the production batch the sample came from. It should match the code on the vial. Example: lot ACE-7203111 for TB-500 10 mg; HYTE writes “Lot Code”, Accurate Test Labs “Batch#”.
COA number, report ID and sample ID
The laboratory’s number for the certificate itself. ILS Laboratories: “COA-2026-QHDFLS”; HYTE Research Division: “Report ID CLP#00007”; Accurate Test Labs: “Sample ID 2607AFL1164.4102”. Use it, with the lot number, when you check a certificate with the laboratory.
Accession number and internal lab ID
The laboratory’s internal tracking number for the sample, separate from the certificate number. Example: “Accession #: ACC-2026-19378” on the ILS BPC-157 10 mg certificate; “Internal Lab ID: ATL-37903” on Accurate Test Labs’ bacteriostatic water certificate.
Access code
A code printed on ILS Laboratories certificates that opens the same certificate on the laboratory’s own portal, so you can compare the two. Our lot pages link to that record. See how to verify a peptide COA.
Date received, analysis date and report issued
When the laboratory received the sample, when it ran the analysis and when it issued the report. They can differ. Example: the GLP-2 Tirz 20 mg certificate was analysed on 15 April 2026 and the report issued on 22 September 2026.
Matrix and appearance
Matrix is the form of the sample: “Lyophilized” (ILS), “Lyophilized Preparation” or “Nasal Spray Solution” (HYTE). Appearance is a visual check: “Good” on ILS certificates, “White Lyophilized Powder” or “Clear Colorless Solution” on HYTE certificates.
Tests requested and method
The panel the client ordered. ILS Laboratories: “Method: Full QC Panel”. HYTE Research Division: “Standard + Endotoxins + Sterility + Heavy Metals” for KPV, “Identity & Quantity” for the sprays. A test that was not requested is not on the certificate.
ISO/IEC 17025
The international standard for the competence of testing and calibration laboratories. Accreditation covers the activities in a laboratory’s published scope; ILS Laboratories’ notes say its accreditation applies to the activities listed in its PJLA scope. Our ILS Laboratories and Accurate Test Labs lot pages state ISO/IEC 17025 accreditation; the HYTE Research Division lot pages do not state one.
Where these certificates come from
Clean Peptide is a US store, cleanpeptide.com, operated by Helios LLC in Winston-Salem, North Carolina (about us). It sells research peptides for laboratory research only, and publishes the certificate for every lot on the product page and in the COA library, where each lot page sets out the results line by line.
