Glossary

The cosmetic peptide glossary.

The vocabulary a formulator and a brand owner actually reach for — the four peptide mechanism classes and the named INCI actives within them, the EU and NMPA labelling and notification terms, the formulation decisions that keep an active stable in a finished base, and the sourcing paperwork behind a launch file. Definitions are drawn from the Pepoderma Journal.

Actives & mechanisms

The four mechanism classes of cosmetic peptide — signal, neurotransmitter-inhibiting, carrier, and enzyme-inhibiting — and the named INCI actives (GHK-Cu, Matrixyl, SNAP-8) a brief specifies within each.

Signal peptide Matrixokine: A signal peptide (also called a matrixokine) is a peptide fragment that mimics the body's own "build more matrix" messages, signalling dermal fibroblasts to upregulate extracellular-matrix proteins such as collagen and fibronectin. In cosmetic formulation it supports firmness and fine-line claims that develop over weeks rather than an immediate effect. Matrixyl (Palmitoyl Pentapeptide-4) is the archetype of this class.
Neurotransmitter-inhibiting peptide: A neurotransmitter-inhibiting peptide mimics the N-terminal end of SNAP-25, a protein in the SNARE complex involved in neurotransmitter release, to modestly soften the muscle-contraction signalling behind dynamic expression lines. It is the topical, far gentler cosmetic analogue of the idea behind injectable expression-line treatment. Argireline (Acetyl Hexapeptide-8) and SNAP-8 (Acetyl Octapeptide-3) are the most-specified examples; the supported claim is expression-line softening, concentrated on forehead and crow's-feet areas.
Carrier peptide: A carrier peptide is built to ferry a trace element into skin, where the element — not the peptide alone — is the functional payload. The defining example is the copper-binding tripeptide family: GHK-Cu (Copper Tripeptide-1) and AHK-Cu, which deliver copper held in the peptide's coordination pocket. A carrier peptide is only as good as its trace-element coordination, which is why the bound-copper fraction matters for this class and not just the peptide content.
Enzyme-inhibiting peptide: An enzyme-inhibiting peptide works by slowing an enzyme rather than sending a signal or delivering a payload. Some tetrapeptides and oligopeptides slow matrix-degrading enzymes (preserving existing collagen), while others act on pigment-pathway steps for a brightening claim. This class is more heterogeneous than the other three and is usually specified by the named INCI active and its documented target rather than by a single archetype molecule.
GHK-Cu INCI: Copper Tripeptide-1 · CAS 89030-95-5: GHK-Cu — INCI name Copper Tripeptide-1 — is a copper-binding tripeptide (glycyl-L-histidyl-L-lysine) that holds a copper ion in a coordination pocket, and is the most-cited cosmetic peptide active in skincare. The blue colour of the powder and reconstituted solutions is the signature of intact copper coordination; the carrier-peptide activity is a property of the intact complex, so the first rule of formulating with it is to keep the copper on the peptide. It is typically used at 0.1–2% finished mass within a pH window of 5.5–7.0 and is incompatible with chelators such as EDTA.
Matrixyl INCI: Palmitoyl Pentapeptide-4 · CAS 214047-00-4: Matrixyl — INCI name Palmitoyl Pentapeptide-4 — is a signal peptide (matrixokine) used for firmness and fine-line claims. A palmitoyl (fatty-acid) chain carries the peptide through the stratum corneum, and the peptide fragment then signals dermal fibroblasts to support collagen and extracellular-matrix proteins. As a trade-supplied solution it is typically used at 3–8% in a working pH window of roughly 5.5–7.0, and it combines without mechanism overlap alongside a neurotransmitter or carrier peptide.
SNAP-8 INCI: Acetyl Octapeptide-3 · CAS 868844-74-0: SNAP-8 — INCI name Acetyl Octapeptide-3 — is a neurotransmitter-inhibiting peptide and the longer-chain (eight-residue) successor to Argireline (Acetyl Hexapeptide-8), extending the SNAP-25-mimicking N-terminal sequence. It is commonly positioned as achieving a comparable or greater expression-line effect at the same use level. As a trade-supplied solution it is typically used at 5–10% in a pH window of 5.0–7.0 and shares Argireline's carrier compatibility, so the two are interchangeable at the formulation-mechanics level.
Palmitoylation Palmitoyl conjugation: Palmitoylation is the conjugation of a palmitic-acid (C16 fatty-acid) chain onto a peptide, signalled by the "Palmitoyl" prefix in INCI names such as Palmitoyl Pentapeptide-4. The lipid tail improves the peptide's passage through the lipid-rich stratum corneum, raising the delivery of an otherwise water-soluble fragment. It is the most common conjugation used to make a signal peptide skin-penetrating in a cosmetic formula.

INCI & regulatory

INCI naming, EU CosIng, EC 1223/2009, CPNP notification, ISO 22716 cosmetic GMP, and the NMPA framework — the label-disclosure and notification vocabulary behind a finished cosmetic product.

INCI International Nomenclature of Cosmetic Ingredients: INCI (International Nomenclature of Cosmetic Ingredients) is the standardised, regulated naming system used on cosmetic product ingredient declarations worldwide — the name that goes on the back-of-pack label, distinct from a peptide's marketing name. A finished product's ingredient list (descending order above 1%, free order below) must use INCI names; there is no legal flexibility to substitute marketing or common names. The INCI name for GHK-Cu is Copper Tripeptide-1, for Matrixyl it is Palmitoyl Pentapeptide-4, and so on, verified against the EU CosIng database and the US PCPC INCI Dictionary.
EU CosIng Cosmetic Ingredients database: CosIng is the European Commission's database of cosmetic substances and ingredients, listing the INCI name, CAS, restrictions under the EC 1223/2009 annexes, and the function category for each ingredient. Brand owners and cosmetic chemists cross-reference an active's INCI name against CosIng before locking the ingredient onto a finished-product label.
EC 1223/2009 EU Cosmetic Products Regulation: EC 1223/2009 is the European Union's Cosmetic Products Regulation, governing the safety, composition, labelling, and notification of cosmetic products placed on the EU market. A brand using peptide actives in a finished product must designate a Responsible Person, assemble a Product Information File (PIF), complete a Cosmetic Product Safety Report (CPSR), and notify the product on the CPNP portal. The supplier's INCI name, CAS, and safety documentation feed those finished-product documents.
CPNP Cosmetic Products Notification Portal: CPNP is the centralised, free EU portal where a brand notifies a finished cosmetic product before placing it on the EU market under EC 1223/2009 — one notification covers all EU/EEA member states. It is a notification, not an approval: there is no review or sign-off, and a reference number is issued immediately on submission. The prerequisite work — a Responsible Person, a completed CPSR by a qualified safety assessor, and the full PIF — must already be in place, and the supplier's peptide-active documentation is referenced within it.
Responsible Person RP — EC 1223/2009 Article 4: The Responsible Person (RP) is the natural or legal person established within the EU who takes legal responsibility for a cosmetic product's compliance with EC 1223/2009 — submitting the CPNP notification, holding the Product Information File, and answering to authorities. A non-EU brand cannot be its own RP unless it establishes an EU entity, so most appoint an EU-based contract RP, distributor, or subsidiary. The peptide-active supplier provides the documentation the RP's safety assessment builds on, but the RP role itself sits with the brand side.
ISO 22716 Cosmetic GMP: ISO 22716 is the international Good Manufacturing Practice standard for cosmetic products, covering production, control, storage, and shipment. EC 1223/2009 recognises compliance with ISO 22716 as evidence of GMP for finished cosmetic products, so it is the framework cited for cosmetic-grade peptide-active operations: documented production records, batch traceability, environmental control, and lot-release procedures.
NMPA Cosmetic Framework China CSAR / IECIC: China's NMPA cosmetic framework, governed by the Cosmetic Supervision and Administration Regulation (CSAR, 2021), requires ingredient-level registration or notification depending on whether an active is a new cosmetic ingredient or already listed on the Inventory of Existing Cosmetic Ingredients in China (IECIC). Established peptide actives such as Copper Tripeptide-1 and Acetyl Octapeptide-3 sit on the IECIC, and a brand references the supplier's INCI documentation to support its finished-product filing.

Formulation

Use level, pH window, emulsion and carrier stability, carrier compatibility, and preservative-system vocabulary — the decisions a cosmetic chemist makes taking an active from sample to a stable finished base.

Stratum corneum: The stratum corneum is the outermost, lipid-rich layer of the skin — the barrier a topical active must cross to reach the living epidermis and dermis below. Because most cosmetic peptides are water-soluble, crossing this lipid layer is the central delivery challenge, which is why signal peptides are often palmitoylated (given a fatty-acid tail) and copper peptides rely on water-based carriers. How a finished formula presents the active to the stratum corneum largely governs how much of it is delivered.
Use level Dosage / inclusion rate: Use level (or inclusion rate) is the percentage of an active in the finished formula, set by the active and the claim rather than by a maximum. GHK-Cu clusters at 0.1–2% finished mass — lower is often better, since higher levels do not give proportionally larger effects and can leave a visible blue tint — while trade-supplied Matrixyl and SNAP-8 solutions are typically used at 3–10%. The right starting point is the low end of the published range for the specific active, confirmed against its technical data sheet.
pH window: The pH window is the finished-formula acidity range within which a peptide active stays intact and active. Most cosmetic peptides prefer a mild window of roughly 5.0–7.0; copper peptides are narrower (about 5.0–6.5) because the copper coordination is disrupted below pH ~4.5. This is why low-pH actives such as L-ascorbic acid and AHA/BHA exfoliants are kept in separate products rather than the same bottle as a copper peptide.
Emulsion / carrier stability O/W and W/O systems: Emulsions disperse oil and water phases, oil-in-water (O/W, lighter lotions and serums) or water-in-oil (W/O, richer creams), and a water-soluble peptide sits in whichever phase is aqueous. A peptide is stable in an emulsion only when the aqueous phase, pH, preservative system, chelators, heat exposure, and packaging are all compatible with the molecule. Stability should be demonstrated in the finished base — through real-time and accelerated testing — not inferred from the powder's COA.
Carrier compatibility: Carrier compatibility describes the active-specific ingredients a formulator must design around to keep a peptide effective in its base. For copper peptides the key flags are chelators (the EDTA family, which strip copper from the complex), strong reductants such as high-strength vitamin C, oxidising preservatives, and pH excursions outside the working window. Surfacing the flag set lets a cosmetic chemist pre-empt the most common "the peptide didn't work" failure modes before stability testing.
Preservative system: A preservative system is the blend that keeps a water-containing cosmetic microbially safe across its shelf life. Most common preservatives (phenoxyethanol, parabens, caprylyl glycol + ethylhexylglycerin, sodium benzoate / potassium sorbate) are generally peptide-compatible at typical use levels. The main risk for copper peptides is hidden EDTA: it is a chelator that appears by default in many preservative blends, so every preservative system should be audited against its full ingredient list.
Cool-down phase: The cool-down phase is the stage of a batch, below about 40 °C, after the heated oil and water phases have been combined and the emulsion has begun to cool. Heat-sensitive ingredients — including peptide actives — are added here so they are not degraded by the higher temperatures of the main processing step. As a rule, peptides belong downstream of any hot or high-shear step, pre-dissolved and added once the base has cooled.

Sourcing & documentation

The cosmetic-grade COA, TSE/BSE-free and allergen declarations, MOQ, lead time, private-label / OEM models, and shipping terms used when a brand qualifies a peptide-active supplier.

Cosmetic-grade COA Certificate of Analysis: A Certificate of Analysis (COA) is the supplier-side document proving the lot received is the lot ordered, listing the tests run on that specific batch and the release decision. A cosmetic-grade peptide COA should confirm product identity (INCI / CAS), lot number, manufacture and re-test dates, appearance, identity by HPLC retention time and mass spectrometry, purity, water content, counter-ion form, and a signed release statement. For copper peptides or formulation-sensitive actives, a brand should also request the copper-to-peptide ratio, colour, or compatibility data relevant to the finished formula.
TSE/BSE-free declaration: A TSE/BSE statement addresses transmissible spongiform encephalopathy and bovine spongiform encephalopathy risk, which is relevant only to ingredients derived from animals that can carry prions. Most modern cosmetic peptides are made by solid-phase synthesis from individually purchased amino-acid building blocks, with no animal-derived materials, so the statement is short — synthetic origin, no animal-derived materials, signed and dated. A useful declaration states scope, source materials, and manufacturing-site detail rather than only asserting "TSE/BSE-free."
Allergen declaration: An allergen declaration states an active's status against the major regulated allergens — and, in the EU, the designated fragrance allergens — so a brand can complete its safety file and labelling. For synthetic peptide actives the risk is cross-contamination at the manufacturing site rather than the molecule itself, so a useful statement names the allergen list referenced, the facility's allergen-handling situation, and whether per-lot testing is available, not just the words "allergen free."
Patch test: A patch test is a finished-product tolerance assessment in which the formulated cosmetic is applied to a small area of skin under controlled conditions to check for irritation or sensitisation before wider use. It is a finished-product step performed by the brand or its testing partner, supporting the safety assessment behind a launch — distinct from the supplier's raw-material documentation, which establishes the active's identity and purity rather than finished-product tolerance.
MOQ Minimum order quantity: MOQ (minimum order quantity) is the smallest amount a supplier will sell of a given SKU, varying by active complexity and demand. Catalogue cosmetic-grade peptide actives commonly start with sample fills around 100 g, with bulk MOQs scaling from there; custom-synthesised actives may start higher. Brand-programme buyers can often negotiate lower MOQs in exchange for forecasted recurring orders against a confirmed brief.
Lead time: Lead time is the interval between order confirmation and shipment. Catalogue cosmetic-grade peptide actives held in inventory ship fastest; make-to-order catalogue actives take longer; and custom-synthesised actives depend on length, modifications, and scale, with heavily-modified sequences requiring the most time. The single biggest schedule risk on a brand launch is usually brand-side decision speed on packaging and label, not the synthesis itself.
Private label / OEM White label · ODM · contract manufacturing: These are partly-overlapping models for getting a finished cosmetic to market without the brand running its own manufacturing: private (or white) label means a brand customises a manufacturer's pre-formulated base; OEM means the manufacturer produces to the brand's supplied specification; and ODM means the manufacturer's R&D develops a custom formula from the brand's brief. In each, the peptide-active supplier is the upstream input, shipping the active and its documentation to whichever party formulates the finished product.
Cold chain: Cold chain is temperature-controlled shipping and storage. Lyophilised (freeze-dried) peptide actives are generally stable at ambient temperature for the few days of typical international transit when suitably packaged, while long-term storage is colder (often −20 °C) per the active's data sheet. Temperature-logged or gel-pack shipping is reserved for temperature-sensitive actives, large bulk shipments with long transit times, or buyers who specifically require it.

Catalogue

Browse the actives

Every active in the catalogue ships with its INCI name, use-level guidance, carrier recommendations, and stability data.

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Journal

Read the field guides

Where these definitions come from — formulator field guides on peptide types, GHK-Cu, INCI naming, emulsion stability, and CPNP.

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The cosmetic peptide glossary.

The cosmetic peptide glossary.

Actives & mechanisms

Signal peptide

Neurotransmitter-inhibiting peptide

Carrier peptide

Enzyme-inhibiting peptide

GHK-Cu

Matrixyl

SNAP-8

Palmitoylation

INCI & regulatory

INCI

EU CosIng

EC 1223/2009

CPNP

Responsible Person

ISO 22716

NMPA Cosmetic Framework

Formulation

Stratum corneum

Use level

pH window

Emulsion / carrier stability

Carrier compatibility

Preservative system

Cool-down phase

Sourcing & documentation

Cosmetic-grade COA

TSE/BSE-free declaration

Allergen declaration

Patch test

MOQ

Lead time

Private label / OEM

Cold chain

Browse the actives

Read the field guides

Let's talk peptides.

The cosmetic peptide glossary.

Actives & mechanisms

Signal peptide

Neurotransmitter-inhibiting peptide

Carrier peptide

Enzyme-inhibiting peptide

GHK-Cu

Matrixyl

SNAP-8

Palmitoylation

INCI & regulatory

INCI

EU CosIng

EC 1223/2009

CPNP

Responsible Person

ISO 22716

NMPA Cosmetic Framework

Formulation

Stratum corneum

Use level

pH window

Emulsion / carrier stability

Carrier compatibility

Preservative system

Cool-down phase

Sourcing & documentation

Cosmetic-grade COA

TSE/BSE-free declaration

Allergen declaration

Patch test

MOQ

Lead time

Private label / OEM

Cold chain

Browse the actives

Read the field guides

Let's talk peptides.