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Why Cu²⁺ Ratio Matters — a field guide. Read →
On the Cu²⁺ ratio. Read →
Biotin-GHK — the GHK metallopeptide with a biotin affinity handle
Overview
Biotinoyl Tripeptide-1 is the Gly-His-Lys tripeptide carrying an N-terminal biotin group — INCI Biotinoyl Tripeptide-1, CAS 299157-54-3, C24H38N8O6S, MW 566.68, the biotin conjugate of the same GHK sequence that underlies GHK-Cu. Cupratec stocks it as the metal-free (apo) biotin-GHK ligand, and it belongs in a copper-coordination atelier for two linked reasons. First, the GHK motif within it retains the histidine-and-N-terminus donor set that coordinates Cu(II), so the conjugate is a copper-loadable ligand, not a generic peptide. Second, the biotin group gives the molecule a streptavidin/avidin affinity handle — the basis of one of the most widely used capture chemistries — which makes biotin-GHK and its copper complex a natural tool for affinity-based study of the GHK metallopeptide, immobilisation onto streptavidin supports, and targeted-delivery investigation. Cupratec supplies it strictly as a cosmetic active; efficacy and any cosmetic claim a finished product makes are the brand's responsibility under its destination-market rules. We ship apo biotin-GHK as a cosmetic-grade Biotinoyl Tripeptide-1 active and as the ligand for copper-loading and affinity work. Because there is no coordinated metal in the apo form, the release file is a peptide-identity-and-purity file: reversed-phase HPLC purity with diode-array detection, identity by mass against the C24H38N8O6S / MW 566.68 expected value, and a moisture/net-peptide-content figure so the loadable stoichiometry — both for copper and for biotin-streptavidin capture — is known before use. The documentation is built to feed a copper-loading workflow directly: a customer charging copper onto biotin-GHK to make the Cu(II) complex knows exactly how much ligand they are starting from. Fills are 20 mg and 50 mg lyophilized vials, with gram-scale lots on the same documentation pack for contract or affinity-reagent development. For the copper-loaded, affinity-grade version of this molecule, see the made-to-order Biotinyl GHK-Cu; the underlying coordination logic is the one in our Cu²⁺ : peptide ratio field note.
Who buys this, and why
Cosmetic-peptide buyers fall into two groups: established beauty / med-aesthetic brands extending an existing line, and private-label clients building a catalog from scratch. The first group usually wants lyophilized peptide material plus stability data in their existing carrier matrix; the second usually wants a finished formulation under their label. Both need INCI naming verified, regulator-specific safety files (CPNP for EU, FDA OTC monograph for US where relevant), and packaging-compatibility data.
Primary buyer fit: medical aesthetic clinics and med spas, academic and contract research laboratories, and regional distributors and re-sellers.
Specifications
Documentation available on request
Regulatory note
Biotinoyl Tripeptide-1 is supplied as a cosmetic-grade INCI ingredient (Biotinoyl Tripeptide-1), the biotin-conjugated apo-ligand of the GHK metallopeptide, not for compounded human-use preparations. Cosmetic-grade material available for beauty private-label brands and finished-product formulators worldwide; INCI name supplied on SDS for cosmetic-notification workflows (CPNP in EU, equivalent registries elsewhere). Finished-product cosmetic claims are the brand's to substantiate under its destination-market rules.
Frequently asked questions
Because biotin-GHK is a copper-loadable ligand with an affinity handle, not a generic cosmetic peptide — it stays inside the coordination remit on both counts. The GHK portion keeps the histidine-and-N-terminus donor set that binds Cu(II), so the conjugate can be charged with copper to form the metallopeptide. The biotin group adds streptavidin/avidin affinity, one of the strongest non-covalent capture pairs in use, which makes biotin-GHK and its copper complex a practical tool for immobilising the GHK motif onto streptavidin supports and for affinity-based study of how the metallopeptide behaves when captured. That combination — a coordinating ligand plus a capture handle — is why it sits beside the copper actives rather than in a general peptide catalogue.
This SKU is the apo (metal-free) biotin-GHK ligand — a white powder with no coordinated copper and therefore no copper colour or d-d band. It is what you load copper onto, or use directly for biotin-streptavidin capture. For the copper-loaded form, Cupratec offers a separate made-to-order Biotinyl GHK-Cu where the copper is coordinated onto the biotin-GHK ligand and the metal loading is characterised on the batch COA. Stocking the apo ligand lets a customer own the copper-loading step and run the affinity chemistry on the metal-free or metal-loaded material as their work requires.
Because the apo form carries no coordinated metal, the release file is a peptide-identity-and-purity file: reversed-phase HPLC purity by diode-array detection, identity by mass against C24H38N8O6S / MW 566.68, and a moisture/net-peptide-content figure so the loadable stoichiometry for both copper and biotin-streptavidin capture is known. If you load copper onto the ligand, the same readouts Cupratec uses on GHK-Cu apply: a correctly loaded complex develops the characteristic blue and a d-d absorbance band, and copper content can be quantified by atomic absorption with reversed-phase HPLC confirming a single coordinated peak. Keep the loading water copper-clean, the pH near-neutral, and chelators and reductants out. The coordination-chemistry logic is set out in our Cu²⁺ : peptide ratio field note.
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