Cosmetic peptide sourcing checklist
Ten checks, answered before payment. The point is not to find a perfect supplier — it is to make the gaps visible while you still have negotiating room.
Part of the cosmetic peptide raw materials pillar.
The ten checks
| # | Check | Pass condition |
|---|---|---|
| 1 | Legal entity | Licence, bank account and invoice entity match |
| 2 | Identity | MS consistent with the declared sequence/complex |
| 3 | Purity | HPLC chromatogram with method and integration |
| 4 | Counter-ion | Stated and consistent with the MS interpretation |
| 5 | Water content | Karl Fischer value reported |
| 6 | Appearance / colour | Within an agreed range against a retained reference |
| 7 | Microbial status | Method and result stated where claimed |
| 8 | Batch linkage | Lot number on vial, COA and invoice |
| 9 | Documentation | COA, MSDS, storage instructions, packaging spec |
| 10 | Commercial terms | MOQ, lead time, claim window and remedy in writing |
Score it
Score each item 0–2. Below 16/20, treat the supplier as unqualified for a repeat program. The score is a conversation tool, not a certification.
Red flags
- "Cosmetic grade" offered as the only specification
- No copper content for a copper peptide
- Colour described as "varies" with no acceptance range
- Microbial claim without a method
- COA reused across batches or products
- No answer on counter-ion
A scoring example
Suppose a supplier answers identity, purity and batch linkage well (2 each), provides water content but no counter-ion (1 and 0), describes colour as "varies" (0), and has no microbial method (0). The score is 7/12 on those six items — not a rejection, but a clear signal that the specification conversation has not happened yet.
When a check fails
Do not average a failure away. A missing identity or batch link is a gate, not a deduction: stop and fix it before commercial negotiation. A missing counter-ion or colour range is a specification gap that can be closed in writing. The distinction matters because one is a supplier problem and the other is a purchasing-process problem.
Editor's take
A checklist that can be averaged is not a gate. Identity and batch linkage should stop the order; everything else is negotiation.
Limitations
This is formulation research guidance; no cosmetic efficacy claim is made. Finished-product safety and claims are the formulator responsibility.
Documenting the decision
Keep the completed checklist with the quotation and the batch COA. If a check was waived, record why and who approved it. The value of the document is not the score — it is the ability to reconstruct, months later, why a supplier was accepted and what was known at the time.
Review the checklist when the product, the packaging or the destination changes. A supplier that passed for a 50 mg vial may not pass for a bulk pack with a different closure and a longer transit route.