Separate the INCI name from stereochemical proof

Ergothioneine is the INCI and common ingredient name; it does not add a separate L prefix on the cosmetic ingredient declaration. Current supplier documents identify Tender's offered material as L-(+)-Ergothioneine with (S)-configuration.

The L declaration describes stereochemistry, while the plus sign describes measured optical rotation under stated conditions. Ordinary HPLC purity alone does not prove enantiomeric purity, so the commercial batch should be supported by a controlled specification and a current result for specific rotation or another suitable stereochemical method.

  • INCI: Ergothioneine
  • Declared supplier form: L-(+) / (S)
  • CAS: 497-30-3
  • Molecular formula: C9H15N3O2S
  • Professional topical cosmetic use

Read purity and appearance on the grade basis

Current supplier documents describe white to off-white crystal or powder and an HPLC purity specification of at least 99%. That HPLC value should not be presented as proof of L-form purity unless the method is specifically capable of separating stereoisomers.

A commercial decision should be tied to a current specification and the COA for the batch that will ship. A representative image can help a buyer recognize the general format, but it cannot prove identity, purity, stereochemistry or batch conformity.

Use formulation guidance, not a registration maximum

Available supplier product literature lists a preliminary suggested use range of 0.1–3%. A separate Chinese cosmetic raw-material safety information record shows a broader use-history value; neither replaces a current controlled TDS, and the use-history value is not a universal formulation recommendation or an EU or US approval.

Confirm the grade-specific TDS, active basis, water solubility, pH and temperature window, order of addition, light protection and storage before pilot work.

Keep antioxidant claims inside the evidence boundary

Antioxidant positioning can inform a cosmetic concept, but raw-material mechanism literature does not automatically substantiate a finished serum or cream claim.

Review the exact grade, use level, complete formula, test design and destination-market wording before publishing radiance, environmental-stress or well-aging claims. Do not reuse food, cardiovascular or medical statements on a cosmetic product page.

Build a current commercial document pack

For initial screening, request the specification, TDS, English SDS and a representative COA. Before purchase or shipment, connect those files to the exact supplier, grade and batch and confirm revision dates.

Storage guidance and physicochemical values must agree across the document set. If they do not, ask the document owner to issue a corrected, controlled version before customer QA approval.

  • Current independent specification
  • Current TDS
  • Destination-appropriate English SDS
  • In-date batch COA
  • Packaging, storage and shelf-life statement