D tier · weak
A 2024 review of topically applied GHK states there is a "surprising absence of clinical studies" for both GHK-Cu and Pal-GHK, and the only human data traceable for palmitoyl tripeptide-1 is a 15-subject supplier study cited second-hand in a Cosmetic Ingredient Review literature review; ClinicalTrials.gov returns zero registered trials. The regenerative and wound-healing literature routinely quoted for it belongs to the copper complex GHK-Cu, a different molecule.
pal-ghk
Palmitoyl tripeptide-1 is the tripeptide glycyl-histidyl-lysine with a palmitic acid chain attached to the N-terminal glycine, sold under the INCI name Palmitoyl Tripeptide-1 and, historically, under the broader label palmitoyl oligopeptide. It is one of the two actives in Sederma's Matrixyl 3000 (with palmitoyl tetrapeptide-7) and is used in leave-on skincare across the UK and EU. Unlike its parent tripeptide's copper complex, the palmitoylated free peptide has essentially no published clinical trial of its own.
// we supply this one
available as a research reagent
≥ 98% HPLC · lyophilised powder · batch certificate published. Grade D above is our own and is not adjusted because we stock it.
the explanation
Pal-GHK is a three-amino-acid peptide with a fatty tail added so it can get into skin. It is a legal, long-established cosmetic ingredient, but almost all the impressive wound-healing and skin-repair research people cite for it was actually done on a different substance - the copper version, GHK-Cu. For the palmitoylated form itself there is barely any published human testing, and a 2024 scientific review said as much in plain terms.
regulatory status
Regulated cosmetic ingredient in the UK and EU; not a licensed medicine anywhere
Palmitoyl Tripeptide-1 is a listed INCI cosmetic ingredient, reviewed by the Cosmetic Ingredient Review as one of fourteen palmitoyl oligopeptides in commercial use, and lawfully used in leave-on skincare in Great Britain under the retained UK cosmetics regime and in the EU and Northern Ireland under Regulation (EC) No 1223/2009 subject to a Cosmetic Product Safety Report and Product Information File. That regulatory status covers topical application to intact skin and nothing else: the cosmetics framework explicitly excludes products intended for ingestion, inhalation, injection or implantation, and MHRA Guidance Note 8 weighs product form alongside claims when deciding medicinal status. There is no MHRA, EMA or FDA approval of the peptide as a medicine. It is not named on the current WADA Prohibited List, though the S0 catch-all covers substances with no approval for human therapeutic use if presented for systemic use, and it has no documented status as a lawful dietary-supplement ingredient in the UK or US. Registry identification is itself unsettled: the CIR report records CAS 147732-56-7 in some sources against CAS 623172-56-5 in the International Cosmetic Ingredient Dictionary.
how it works · proposed mechanism
GHK (glycyl-histidyl-lysine) occurs naturally in human plasma, saliva and urine and declines with age; it derives from the alpha-2 chain of type I collagen and behaves as a matrikine. The free tripeptide is hydrophilic and penetrates skin poorly, so cosmetic chemistry has taken two different routes to fix that - complexing it with copper (GHK-Cu) or acylating it with palmitic acid (Pal-GHK). Those two solutions produce chemically and pharmacologically different molecules, and only one of them has controlled human trials.
Matrikine signalling to fibroblasts
GHK is proposed to modulate the balance between synthesis and breakdown of collagen and other extracellular matrix components, including effects on metalloproteinases, and to influence fibroblast behaviour after injury. Pickart's reviews report up- and downregulation of several thousand human genes by the peptide. Almost all of that transcriptomic and cell-biology work was performed with the copper complex, not the palmitoylated peptide.
Palmitoylation solves permeability, not evidence
The 2024 BioImpacts review of topically applied GHK is explicit that unmodified GHK has poor skin permeability despite cellular activity, and that metal complexation and chemical modification with a hydrophobic moiety increase permeability. Palmitoylation is therefore a formulation fix for delivery. The same review notes that published information on the properties of GHK-Cu and Pal-GHK remains sparse and that there is a surprising absence of clinical studies using them.
Copper is not incidental to the parent's biology
GHK-Cu is a copper(II) chelate, and much of the mechanism attributed to GHK - redox activity, copper delivery to enzymes such as lysyl oxidase and superoxide dismutase, antioxidant and pro-angiogenic behaviour - depends on the bound metal. Pal-GHK carries no copper. Transferring GHK-Cu findings to Pal-GHK assumes the metal is dispensable, which the published mechanism does not support.
What the human record for Pal-GHK actually is
The CIR literature review records a 15-subject study in which palmitoyl tripeptide-1 produced statistically significant reductions in wrinkle length and depth, without publication details or independent verification, and lists in-use concentrations at trace levels. The supplier of Matrixyl 3000 claims an age-appearance gain equivalent to about two years in one month and up to 5.5 years after two months, again from in-house data on the two-peptide blend rather than on Pal-GHK alone.
what’s reported
evidence shape
7 sourcesThe composition of the cited literature by study type. This describes the shape of the evidence, not its quality — and it does not by itself set the grade.
⚠ the catch
This is a textbook borrowed-evidence case. The wound-healing and skin-regeneration literature quoted for PAL-GHK - diabetic and venous ulcer trials, post-laser skin studies, the claim that the peptide resets several thousand genes - was generated with GHK-Cu, a copper(II) chelate that differs from the palmitoylated peptide in charge, coordination chemistry and redox activity, and whose mechanism is partly attributed to the copper itself. For palmitoyl tripeptide-1 as sold, a 2024 review of topically applied GHK states outright that there is a surprising absence of clinical studies for both GHK-Cu and Pal-GHK, ClinicalTrials.gov returns zero registered studies, and the only human numbers traceable are a 15-subject supplier study reported second-hand in a CIR literature review plus in-house blend data from the Matrixyl 3000 supplier. On top of that, the identity of the material is not fully settled - the CIR report notes CAS 147732-56-7 competing with CAS 623172-56-5 in the industry dictionary. A compound whose entire evidence base is topical cosmetic use, sold as a vial for reconstitution, has no evidence for the route it is being sold for.
key published findings
- Mortazavi 2024 (BioImpacts), a review dedicated to topically applied GHK, states that despite wide cosmetic use of GHK-Cu and Pal-GHK there is a surprising absence of clinical studies using them, and that published information on their properties is sparse.
- The same review confirms the rationale for the palmitoyl group: unmodified GHK has poor permeability, and metal complexation or hydrophobic modification is what increases it.
- The 2012 CIR literature review on palmitoyl oligopeptides records a 15-subject study of palmitoyl tripeptide-1 reporting statistically significant reductions in wrinkle length and depth, with no publication citation, and lists in-use levels for palmitoyl peptides in cosmetics at trace levels.
- The CIR review also reports that palmitoylated peptides diffuse into epidermis and dermis in vitro but do not penetrate beyond the dermis, with no significant transcutaneous penetration.
- Croda/Sederma lists Matrixyl 3000 as Palmitoyl Tripeptide-1 with Palmitoyl Tetrapeptide-7, claiming an appearance-age gain of about two years in one month and up to 5.5 years after two months - manufacturer data on the blend, not on Pal-GHK alone.
- ClinicalTrials.gov returns zero registered studies for palmitoyl tripeptide or Matrixyl searched as terms.
limitations of the evidence
- No peer-reviewed, independently conducted controlled trial of palmitoyl tripeptide-1 as a single active has been published; PubMed hits for the term are formulation, analytical or in vitro papers.
- The regenerative evidence base belongs to GHK-Cu, and the copper is mechanistically load-bearing rather than incidental, so the transfer to a copper-free palmitoyl analogue is unjustified.
- The one human result attributed to the ingredient comes from a 15-subject study known only through a second-hand summary, with no protocol, blinding description, endpoint definition or statistics available for scrutiny.
- Manufacturer figures for Matrixyl 3000 describe a two-peptide blend and cannot be attributed to palmitoyl tripeptide-1 alone.
- Registry identity is inconsistent between the industry dictionary and other sources (CAS 623172-56-5 versus 147732-56-7), which complicates verifying what a given vial contains.
- No human pharmacokinetic, systemic exposure or safety data exist for any route other than topical application to intact skin.
documented safety signals
- The CIR review of palmitoyl oligopeptides found no significant transcutaneous penetration in vitro and reported in-use levels in cosmetics at trace concentrations, consistent with a low systemic exposure profile by the topical route.
- No characteristic irritation or sensitisation signal specific to palmitoyl tripeptide-1 is documented in the CIR record beyond the general palmitoyl-peptide dataset.
- Histidine-containing peptides are metal-binding by design; a copper-free palmitoyl-GHK applied to skin may chelate endogenous transition metals, and the consequences of that have not been studied in humans.
- There are no safety data for injection, ingestion or inhalation of this peptide; the absence of reported harm by those routes reflects the absence of any study, not evidence of safety.
identity
| full name | Palmitoyl tripeptide-1 (palmitoyl-Gly-His-Lys, Pal-GHK) |
| category | Cosmetic |
| modality | peptide |
| formula | C30H54N6O5 |
| molar mass | 578.8 g/mol |
| cas | 147732-56-7 |
| sequence | Palmitoyl-Gly-His-Lys |
laboratory handling
| storage | Lyophilised powder is stored desiccated at -20 °C, protected from light and moisture. Palmitoylated peptides are surface-active and prone to adsorption losses, so laboratory preparations are handled in low-binding vessels. Handling information only. |
| solubility | Amphiphilic: poorly soluble in water alone, and laboratory preparations typically use a small proportion of a co-solvent before dilution into aqueous buffer. |
| co-studied with | Almost always encountered as half of the Matrixyl 3000 pairing with palmitoyl tetrapeptide-7, and frequently formulated with pal-KTTKS; no published trial isolates the contribution of palmitoyl tripeptide-1 within any of those combinations, so blend claims should not be read as evidence for this peptide. |
Handling information describes laboratory practice for a research reagent. It is not a preparation guide for use in humans.
the receipts
7 citedCosmetic Ingredient Review Expert Panel · 2012 · official
Medicines and Healthcare products Regulatory Agency · 2025 · official
BioImpacts · 2024 · review
BioMed Research International · 2015 · review
Frontiers in Medicine · 2026 · systematic review
PubChem, National Library of Medicine · 2026 · reference
Croda Beauty / Sederma · 2026 · press release
Sources marked tertiary or press release are the weakest citations on this page.
others in Cosmetic