A purchasing team can receive three apparently matching descriptions for one peptide: an INCI name on a cosmetic brief, a CAS number on a supplier sheet and a short sequence in a laboratory request. Those fields answer different questions. Before comparing quotations, establish exactly what will arrive in the container and how its identity will be confirmed.
Read each identifier for what it actually says
INCI: a labeling name
International Nomenclature of Cosmetic Ingredients (INCI) supports ingredient naming on cosmetic products. It is useful for aligning a formulator’s brief with the intended label. An INCI entry alone does not identify every commercial detail of a supplied ingredient. The European Commission’s CosIng database explicitly warns that an ingredient appearing in its inventory is not, by itself, approval for cosmetic use. Check the applicable legislation and destination market separately.
CAS: a chemical registry reference
A CAS Registry Number can narrow a search, but the number must match the supplier’s stated substance. Ask whether the proposed material is a free peptide, a particular salt, or a preparation containing other components. For a blend, a single number may describe only one constituent. Record the exact name printed on the quotation and certificate rather than transferring a number from another product page.
Sequence and modifications: the molecular specification
For a defined peptide, the amino-acid sequence and terminal or side-chain modifications may be essential to identity. The brief should spell out stereochemistry where relevant, termini, counter-ion or salt form, and any conjugation. A supplier’s short trade name may leave these details out. Ask which analytical evidence is available for the material being quoted; a chromatographic purity figure does not, on its own, settle identity.
Connect the name to the supplied form
Cosmetic peptide ingredients may be sold as a neat powder, a diluted solution or a premix. Confirm the peptide content basis, carrier, preservative or solvent, and intended grade before entering a material into a formulation bill of materials. The supplied form can affect the purchasing specification, storage assessment and finished-product ingredient declaration. The FDA’s cosmetic GMP checklist calls for raw materials to be labeled for identity and lot status and examined against acceptance specifications.
A usable identity request
- State the proposed INCI name and target markets.
- Provide the complete chemical name or sequence, modifications and salt form if known.
- Ask the supplier to identify every component of the supplied preparation.
- Request a batch-specific COA and the method used to establish identity.
- Check that the quotation, sample label and documentation all describe the same material.
Use our cosmetic peptide catalog to find candidates, then send the precise identity requirements in a technical enquiry. A catalog title is a starting point, not a substitute for the agreed specification.
Frequently asked questions
Does an INCI listing mean a peptide is permitted in every market?
No. CosIng is informational. Permission, restrictions, safety assessment and labeling must be checked for each destination market and finished product.
Can a CAS number replace the peptide sequence?
Use both when available. Confirm that the number refers to the exact chemical form offered and record sequence modifications separately.
What if the sample is a premix rather than pure peptide?
Request the complete supplied composition and the basis on which peptide content is stated. Evaluate the premix against the intended formula and purchase specification.
Keep the final identity decision in the purchase file, alongside the offered batch documents and the market review.