Documents that arrive after the goods are worth very little. By then the money has moved, the batch is in your building, and the only question left is whether you accept it. A document package is a decision tool, and a decision tool has to arrive before the decision.
This is the checklist we would want if we were the buyer: what should exist before payment, what should exist before the batch leaves, what travels with it, and what you keep on file afterwards. It is written for research-grade lyophilized vials and for cosmetic peptide raw material, and it assumes nothing about who the supplier is.
1. The checklist, by stage
The order matters more than the list. Asking for everything at once produces a folder; asking in stages produces a decision at each gate.
| Stage | What you should have | What it lets you decide |
|---|---|---|
| Before quotation is comparable | Product specification sheet; a representative COA; SDS/MSDS | Whether two quotations describe the same material at all — salt form, purity basis, assay basis, packaging |
| Before you commit | Confirmation of which batch will be supplied; whether that batch already exists or is yet to be produced; what testing that batch will carry | Whether the documents you were shown will apply to the goods you receive |
| Before it ships | Batch-specific COA naming the actual lot; HPLC chromatogram with peak table; mass spectrum; water content where relevant | Whether to release the shipment, or to hold and ask |
| With the shipment | Packing list matching vial count and fill; labels matching the COA batch; storage and handling conditions stated | Whether what arrived is what was documented |
| Keep on file | All of the above plus retain samples and your own incoming-inspection record | Whether batch 3 is still the same as batch 1, twelve months from now |
The single most common failure is not a missing document. It is a document from the wrong stage — a representative COA presented at the "before it ships" gate, where only a batch-specific one answers the question.
2. What each document actually supports
Each row below has a page of its own, because each answers a different question and none of them substitutes for another.
| Document | Supports | Does not support |
|---|---|---|
| Certificate of Analysis | Batch results against a stated specification | Anything about a different batch. How to read one line by line |
| HPLC chromatogram + peak table | Chromatographic purity under the stated method, and what the impurity profile looks like | Identity, content, or salt form. Document review guide |
| Mass spectrum | Molecular identity confirmation | Purity or quantity. How identity is confirmed per batch |
| Content / assay result | How much peptide is actually present | Cannot be inferred from purity. Content vs total vial weight |
| Salt form / counterion data | What fraction of the weight is counterion | Purity or biological equivalence. TFA, acetate and salt form |
| SDS / MSDS | Handling, storage and transport safety information | Quality, purity or suitability for your process |
| Specification sheet | What the supplier commits to on every batch | What this particular batch measured |
| Filling record / fill amount | That the stated fill was recorded during filling | An independent assay of what is in the vial. Cake, fill volume and reconstitution |
3. Five things that go wrong, and the question that catches each
- The COA is for a different lot. Ask: does the batch number on this certificate match the batch number that will be on the label? If the batch does not exist yet, say so — that is a legitimate answer and it changes the gate, not the deal.
- Purity is quoted, content is not. Ask: what is the peptide content, on what basis, and by what method? A high purity figure with no content figure is half an answer.
- The basis is unstated. Ask: as-is or anhydrous? Salt-free or as the salt? Two certificates that look different often differ only here.
- Test scope quietly narrows between batches. Ask: which items are release tests on every batch, and which were done once? Both are fine; not knowing which is which is not.
- The sample and the shipment are not from the same population. Ask: how were the tested vials selected? How QC vials are selected covers what a defensible sampling plan looks like.
4. If you intend to re-test on arrival
Buyers who plan their own incoming testing should say so before the order, not after. It changes what is worth asking for.
- Ask for the method information you will need to make your result comparable — the column type, detection wavelength and mobile phase composition. Full method development parameters are usually treated as proprietary by any supplier, ours included; what you need for comparability is narrower than a full method transfer.
- Ask for enough retain material to test without consuming saleable stock. Retain samples and reconstitution verification sets out how much is reasonable.
- Agree in advance what happens if your result and the certificate disagree, and by how much. A tolerance agreed before shipment is a commercial term; the same conversation after arrival is a dispute.
5. What we provide, and when
For our own supply, so that this page is not purely theoretical: specification sheet, SDS/MSDS and a representative COA can be provided at enquiry stage. Batch-specific COA, HPLC chromatogram with peak table, and mass spectrum are issued against the lot being supplied. Where a project requires independent third-party testing, that is arranged per batch and the report is supplied with the material rather than summarised.
Two limits stated plainly, because a checklist that only lists what a supplier can do is marketing rather than a checklist. Method development parameters beyond the comparability information above are not released; method development is chargeable work in its own right. And documents are issued for the material as supplied — research-grade lyophilized material is supplied for laboratory research use only, not for human or veterinary use, and no document we issue changes that.
Current published examples are in our document centre. To request the package for a specific project, use the documentation and quotation request form.
Frequently Asked Questions
What documents should I have before paying for a peptide order?
Before comparing quotations: specification sheet, a representative COA, and SDS/MSDS. Before committing: confirmation of which batch will actually be supplied and what testing it will carry. Before shipment: a batch-specific COA naming that lot, with chromatogram and mass spectrum. A representative COA is not a substitute for a batch-specific one at the shipment gate.
Is a Certificate of Analysis enough on its own?
No. A COA reports results against a specification for one batch. It does not tell you how the tested vials were selected, whether the reported basis matches the standard you are comparing against, or what was tested once versus on every batch. Those are separate questions with separate answers.
What if the supplier cannot give a batch-specific COA yet?
That is a normal answer when the batch has not been produced. It is only a problem if it is presented as though it were a batch document. Treat it as a change of gate: agree what the batch COA must show, and make shipment conditional on it.
Can I ask for the full analytical method?
You can ask, and most suppliers will decline. What you actually need for comparability is narrower: column type, detection wavelength and mobile phase composition. Full method development parameters are chargeable work and are generally treated as proprietary.
How much retain sample is reasonable to request?
Enough to run your intended tests without consuming saleable material, agreed before the order rather than after. The quantity depends on which tests you plan and how much each consumes.
What should I do if my incoming result disagrees with the certificate?
Check the basis and method first — as-is versus anhydrous, salt form, and which peaks are included in the purity figure account for most apparent disagreements. If those match and the results still differ, the productive route is the tolerance and re-test procedure agreed before shipment.
Does a document package make research-grade material suitable for human use?
No. Research-grade lyophilized peptide material is supplied for laboratory research use only and not for human or veterinary use. Documentation describes what was measured; it does not change what the material is approved for, and buyers remain responsible for intended use, importation and destination-market compliance.
If peptide documentation is new to you, a shorter orientation to the four document types covers what a COA, an HPLC or MS report and an SDS each are, before you work through the stages above.