Palmitoyl Tripeptide-1 & Palmitoyl Tripeptide-5
Palmitoyl Tripeptide-1 & -5 — evidence, collagen-signal claims & status

Class: peptide
INCI name: Palmitoyl Tripeptide-1 & Palmitoyl Tripeptide-5
Synonyms: - Palmitoyl Tripeptide-1 = Pal-GHK (palmitoylated Gly-His-Lys)
trade name Biopeptide CL
trade name SYN-COLL (DSM).
- INCI: as named. (Both are cosmetic INCI ingredients.)
Trade names: Biopeptide CL
SYN-COLL
Function tags: skin appearance (cosmetic)
fine lines & firmness
(reference:) collagen/ECM signalling
Overall evidence grade: C
WADA prohibited: no
Last updated: 2026-07-20

In brief: Palmitoyl Tripeptide-1 (Pal-GHK) and Palmitoyl Tripeptide-5 (Pal-KVK / SYN-COLL) are signal peptides proposed, like Matrixyl, to tell skin fibroblasts to make collagen — Tripeptide-1 as a GHK matrikine, Tripeptide-5 by activating TGF-β. They are mechanistically plausible and very well tolerated, but the standalone human evidence is mostly manufacturer/in-vitro (thinner than Matrixyl's single split-face RCT), and most of the human data for Tripeptide-1 is actually for the Matrixyl 3000 combination, not the peptide alone. They are cosmetic ingredients only.

## Identity two synthetic **palmitoylated tripeptide** signal peptides (3 aa + C16 palmitoyl tail; < 40 aa → peptides), each proposed to signal fibroblasts to build extracellular matrix — but by **different routes**:
- **Tripeptide-1 (Pal-GHK):** a **matrikine** — the GHK sequence derives from the C-terminal region of the α2 chain of collagen I and acts as a repair signal via the TGF-β pathway.
- **Tripeptide-5 (Pal-KVK):** a **TGF-β activator** — mimics the KRFK sequence of **thrombospondin-1 (TSP-1)**, which activates latent TGF-β. ## Development & history - **Palmitoyl Tripeptide-1** was developed by **Sederma** (France) as part of its Matrikine platform (late 1990s; "Biopeptide CL"), and became prominent as a component of **Matrixyl 3000** (launched ~2003), paired with **Palmitoyl Tetrapeptide-7 (Pal-GQPR / Rigin)**, an anti-inflammatory peptide.
- **Palmitoyl Tripeptide-5** was developed by **DSM** (Pentapharm) as **SYN-COLL**.
- Both have only ever been **cosmetic** ingredients, never drugs. ## Mechanism (as proposed) - **Palmitoyl Tripeptide-1:** the GHK matrikine is proposed to bind fibroblast receptors (TGF-β / integrin signalling) and upregulate collagen I/III, fibronectin and elastin — mimicking the collagen-degradation repair signal without actual degradation.
- **Palmitoyl Tripeptide-5:** proposed to mimic thrombospondin-1 and activate latent TGF-β, which in turn signals procollagen synthesis; also reported to reduce MMP activity.
- In both, the palmitoyl tail aids skin penetration; most characterisation is in vitro, and the in-vivo effect is modest.

## Related reading

These collagen-signal peptides sit alongside the soothing, redness-calming peptides — including the Matrixyl 3000 partner Palmitoyl Tetrapeptide-7 — catalogued in our [anti-inflammatory peptides reference list](/learn/anti-inflammatory-peptides). For where these signal peptides rank among the cosmetic peptides by evidence, see [cosmetic peptides ranked by evidence](/learn/best-peptides-for-skin) and the [Matrixyl explainer](/learn/matrixyl-explained), whose 3000 blend they belong to.

Evidence grades by outcome:
outcome: Topical: appearance of fine lines / firmness — Palmitoyl Tripeptide-1
grade: C
base: Mechanistic (GHK matrikine, TGF-β) + Matrixyl 3000 combination studies
effect: Plausible improvement
caveat: Standalone human RCT is thin; most human data is for the Matrixyl 3000 combo, not the peptide alone
outcome: Topical: appearance — Palmitoyl Tripeptide-5 (SYN-COLL)
grade: C
base: Manufacturer studies + TSP-1/TGF-β mechanism
effect: Preliminary improvement
caveat: Manufacturer-dominated; preliminary
outcome: Collagen / ECM stimulation (both)
grade: C
base: In-vitro (TGF-β pathway; collagen I/III, fibronectin)
effect: Stimulates in vitro
caveat: In vitro; reported magnitudes are largely manufacturer-derived
outcome: "Collagen-boosting" / "rebuilds collagen" structural claim
grade: D
base: Marketing claim
caveat: The controlled human endpoints are appearance-based — fine lines, wrinkle depth, scored firmness. Collagen synthesis was never measured in human skin; the collagen data are in-vitro fibroblast assays with largely manufacturer-derived magnitudes.
outcome: Safety (both, topical)
base: Broad cosmetic use
effect: Well tolerated, non-irritating
caveat: Good safety; no photosensitivity; suitable for sensitive skin

Legal status:
region: EU
status: Lawful cosmetic
note: lawful cosmetic ingredients (EU Regulation (EC) 1223/2009; US cosmetic law), sold over-the-counter worldwide. No injectable/research lane. Sellable as cosmetics — the constraint is the claims.

Cosmetic claims:
allowed: for the **appearance** of firmer, plumper, smoother skin
helps reduce the **look** of fine lines.
forbidden: boosts / stimulates / increases **collagen**
collagen-boosting
activates TGF-β
rebuilds collagen
by function

Note: Cosmetic signal peptides — the "collagen-signal" archetype (like Matrixyl #28), with the same claim trap. Two related but distinct collagen-signalling peptides. Mechanistically among the better-grounded cosmetic peptides and very well tolerated — but the standalone human evidence is mostly manufacturer/in-vitro, and the "collagen boosting" claim is the structural-claim trap.

Sources:
Sederma / Croda — Matrixyl 3000 (Pal-GHK + Pal-GQPR) technical and clinical documentation.
DSM — SYN-COLL (Palmitoyl Tripeptide-5) documentation.
Pickart L, et al. — foundational GHK matrikine research (mechanistic grounding for Pal-GHK).
Robinson LR, et al. (2005) — the class-defining signal-peptide RCT (Matrixyl / Pal-KTTKS).