Read it in eight checks: the batch matches your vial, the molecule is named exactly, the purity figure states its method, mass spectrometry confirms identity, the powder's other contents are accounted for, contaminants are reported with units and limits, every result is judged against a specification, and a laboratory signs and dates it.
A certificate of analysis is a laboratory's record of what one batch of material was measured to be. It is the only document that turns "99% pure" from a claim into a result, and it only does that if it can be tied to the vial in your hand and if the measurements on it are the right ones.
Most certificates fail on one of those two counts rather than on the numbers. The eight checks below go through a certificate in the order that catches the most problems earliest. The certificate checker on this site runs the same list automatically on pasted text.
Start with the batch or lot number, before reading any result. It should be printed on the certificate and on the vial, and they should be the same. A certificate for a different batch describes a different vial, however good its numbers are.
A certificate with no batch number at all cannot be tied to anything. It may be genuine for some batch, but nothing connects it to yours, which makes it a description of a product rather than a measurement of one.
The product name is not identity. Look for the amino acid sequence, the molecular formula or the molecular weight, and check them against an independent reference such as PubChem. Many research peptides exist in more than one form — acetylated or amidated, with or without a modifying group — and the forms differ in mass and behaviour.
For BPC-157 the reference values are a molecular formula of C62H98N16O22, an average molecular weight of 1419.5 and a monoisotopic mass of 1418.70. A certificate quoting something else is describing something else.
Purity on a peptide certificate is almost always reversed-phase HPLC: the sample is separated on a column, detected by ultraviolet absorbance (typically around 214–220nm, where the peptide bond absorbs), and the main peak's area is reported as a percentage of all the peaks. A figure such as 99.3% means the target peak is 99.3% of what the detector saw.
The method matters because the number depends on it. A short, shallow gradient can merge impurities into the main peak; a wavelength the impurities barely absorb at can hide them. A purity figure without its method cannot be reproduced or compared, and a certificate that includes the chromatogram itself lets you see whether the main peak is clean or has shoulders the integration absorbed.
Purity also has a limit to what it says. It measures how much of the sample is one species. It does not say which species, and it does not say how much of the powder is peptide. The next two checks cover those.
Mass spectrometry weighs the molecule, which is how identity is confirmed. A certificate should give an observed mass and the theoretical mass it was compared against. HPLC alone cannot do this: it can read 99% on the wrong peptide, and a near-miss sequence missing one residue can look clean on a trace.
Electrospray mass spectrometry usually reports peptides as several charged ions rather than one, so the numbers on the certificate may not look like the molecular weight at first. Each ion is the monoisotopic mass plus one proton (1.00728) per charge, divided by the charge. For BPC-157 that gives the values below; a certificate showing 710.36 is reporting the doubly charged ion, not a different molecule.
| Ion | Charge | Expected m/z |
|---|---|---|
| [M+H]⁺ | 1 | 1419.71 |
| [M+2H]²⁺ | 2 | 710.36 |
| [M+3H]³⁺ | 3 | 473.91 |
A lyophilised peptide is not 100% peptide. Peptides purified by reversed-phase HPLC usually leave as trifluoroacetate salts, and the dried powder takes up water from the air. Both add weight. Net peptide content — measured by amino acid analysis or nitrogen content — is the figure that says how much of the powder is the peptide itself.
Water content is usually measured by Karl Fischer titration, and the counter-ion may be reported as TFA or acetate content. A certificate with none of these can be 99% pure and still describe a vial holding noticeably less peptide than its label, which is the arithmetic the purity-adjusted cost calculator does.
Heavy metals should be reported element by element — lead, mercury, arsenic and cadmium at minimum — each with a figure, a unit (ppm, µg/g or mg/kg) and the limit it was judged against, by a named method such as ICP-MS. "Complies" or "passes" with no numbers is a conclusion, not a result.
For context, the international guideline regulators use for elemental impurities in medicines, ICH Q3D, sets limits for injectable products as permitted daily exposures. Those figures belong to medicines and their dosing, not to research materials; they are here to show what a properly stated limit looks like, not as a threshold for use.
| Element | Parenteral PDE |
|---|---|
| Lead (Pb) | 5 µg/day |
| Arsenic (As) | 15 µg/day |
| Mercury (Hg) | 3 µg/day |
| Cadmium (Cd) | 2 µg/day |
Thorough certificates also report endotoxin, by the LAL test in endotoxin units per milligram, and residual solvents from synthesis such as acetonitrile and TFA. Their absence is worth noticing rather than assuming they were fine.
A result means little without the specification it was judged against. A complete certificate has two columns: the acceptance criterion (≥98.0%, NMT 0.5%, "conforms to reference spectrum") and the result. That is what lets you see a result that only just passed, or a specification loose enough that passing it says little.
If a certificate lists results with no specifications, it has told you what was measured but not what would have counted as a failure.
The certificate should name the laboratory that performed the analysis and carry an analyst and an approving signatory. The date of analysis should fall after the batch was manufactured and not so long ago that a retest date has passed. Storage conditions and a retest or expiry date say how long the result is meant to hold.
An unattributed, undated certificate has nobody standing behind it and no point in time it describes.
Some problems only show across documents. The same chromatogram image on certificates for different batches or different compounds. Purity figures that are suspiciously round, or identical to two decimal places across batches. A molecular weight that does not match the compound. Results with no units. A date before the batch existed. A laboratory that cannot be found.
None of these proves a certificate false, and a certificate with none of them can still be wrong. A certificate is a document; it can be complete and still be fiction. The only proof of what is in a vial is an independent analysis of that vial.
We make our peptides in our own laboratory in Australia. Every batch is tested here before release — HPLC purity of 99% or better, identity by mass spectrometry and a screen for lead, mercury, arsenic and cadmium — and the results are recorded against the batch number on the vial.
A laboratory's record of what one batch was measured to be: its identity, purity and contaminants, each judged against a specification, signed and dated. It describes one batch, so it only applies to your vial if the batch numbers match.
A batch number, the compound's identity (sequence, formula or molecular weight), HPLC purity with its method, mass-spectrometry identity, heavy metals with units, a specification beside each result, the testing laboratory, a signatory and a date.
The batch or lot number on the certificate must match the one printed on the vial. A certificate for another batch, or with no batch number at all, tells you nothing about the vial you have.
The share of the detected peak area that is the target peptide, measured by reversed-phase HPLC with UV detection. It says how much of the sample is one species, not which species it is or how much of the powder is peptide.
Because HPLC cannot confirm identity. Mass spectrometry weighs the molecule and compares it with the theoretical mass, which is how a wrong or near-miss sequence is caught even when purity reads 99%.
Electrospray mass spectrometry reports multiply charged ions. BPC-157, monoisotopic mass 1418.70, appears at m/z 710.36 as its doubly charged ion and 473.91 triply charged. Same molecule, different charge.
Purity is the share of the peptide material that is the target sequence. Net peptide content is the share of the whole powder that is peptide, after counter-ion salt and water. A vial can be 99% pure with a net peptide content well below 100%.
Yes. A certificate is a document and can be complete and still untrue. Reused chromatograms, identical figures across batches and untraceable laboratories are warning signs. Only independent analysis of the vial proves its contents.
This guide is for educational purposes and is not medical advice. OzPeptides products are sold for research and laboratory use only, not for human consumption. 18+ only.