Pal-GHK Research

Pal-GHK research is small, and most of it is not about Pal-GHK on its own. The compound is palmitoyl tripeptide-1, a copper-free, palmitoylated derivative of the GHK tripeptide. The name invites several errors. One reads GHK-Cu evidence as Pal-GHK evidence. Another reads results for Matrixyl 3000, a two-peptide blend, as results for this single ingredient. This article describes what has been published, not outcomes anyone should expect.

What Pal-GHK is

Pal-GHK is N-palmitoyl-glycyl-L-histidyl-L-lysine. CAS 147732-56-7 resolves to PubChem CID 10231864, C30H54N6O5, 578.8 g/mol. The CIR Expert Panel's 2014 cosmetic safety assessment records the same CAS number.^[1] The formula contains no copper. Research-grade Pal-GHK is commonly supplied as the acetate salt.

Several related molecules circulate under overlapping names:

• GHK, the unmodified parent tripeptide, C14H24N6O4.
• GHK-Cu, copper tripeptide-1, C14H21CuN6O4-, which contains copper and is not palmitoylated.
• Pal-GHK, which is palmitoylated and contains no copper.
• Palmitoyl copper peptide, which is both palmitoylated and copper-complexed, and which has been studied separately in vitro.^[2]

A search result naming a palmitoyl copper peptide is therefore not a result about Pal-GHK. The legacy INCI name, palmitoyl oligopeptide, is ambiguous in the same way. The CIR report records no peptide sequence for palmitoyl oligopeptide in the VCRP database or in the Personal Care Products Council use survey.^[1] The report states that the sequence could be either GHK or the elastin hexapeptide VGVAPG.^[1] The Panel addressed that gap by restricting its safe finding to the named sequences GHK, VGVAPG and GQPR.^[1]

Why GHK-Cu research does not transfer

PubMed returns about 80 records for the search term GHK-Cu. The exact term palmitoyl tripeptide-1 returns 2 records, and palmitoyl GHK returns 4. This compound is indexed under several names, so neither figure is a full count of its literature. ClinicalTrials.gov lists three studies for GHK-Cu and none for palmitoyl tripeptide-1. Copper is central to the GHK-Cu literature and is absent from this molecule. Nothing in the GHK-Cu record is evidence about Pal-GHK.

How Pal-GHK is thought to work

The proposed mechanism is matrikine signaling, in which a short matrix-derived sequence prompts fibroblasts toward extracellular matrix synthesis. Sederma-authored work reported a strong collagen synthesis signal in human fibroblasts in vitro, and near-total collagen preservation in UVA-irradiated human skin samples ex vivo.^[1][3] The same assessment reports a 450-gene activation profile oriented toward keratinocyte anchoring, differentiation and matrix synthesis in vitro.^[1] The report sources that profile to a corporate synopsis and a consumer web page, and states that no further details were provided.^[1] All three findings trace to the ingredient's manufacturer.

Explanations of how this compound works are often borrowed from the original Matrixyl, a Sederma trademark for a different peptide, pal-KTTKS. In vitro biophysics undercuts that borrowing. C16-KTTKS forms flat tapes and extended fibrils with high beta-sheet content, and it stains with Congo red.^[4] C16-GHK instead forms crystal-like aggregates with lower beta-sheet content, and it does not stain.^[4] The collagen-stimulating effect of C16-KTTKS has been tied to that self-assembly in human fibroblasts in vitro.^[5] C16-GHK does not self-assemble that way.^[4] Two of that paper's six authors are university chemists, and four are Procter and Gamble scientists.^[4]

A separate academic group synthesized a set of acetyl, lipoyl and palmitoyl KTTKS analogues and tested them in fibroblast assays in vitro.^[6] Three analogues that supported cell growth showed no concentration-activity relationship in the collagen and DNA biosynthesis assays.^[6]

Human research on Pal-GHK

No trial of Pal-GHK is registered on ClinicalTrials.gov. That registry returns no studies for palmitoyl tripeptide-1 and none for Matrixyl. No halted or withdrawn entry exists there, because nothing was ever registered there.

Two human results for the ingredient alone can be traced, and both come from Sederma, which owns the Matrixyl trademark. In 23 healthy female volunteers, palmitoyl tripeptide-1 in a vehicle was compared against the vehicle alone.^[1][3] Skin thickness rose by about 4 percent on ultrasound echography over four weeks.^[1][3] The increase was statistically significant. That result sits inside a manufacturer-authored review rather than a dedicated trial report, and the endpoint is instrumental.

The second is the origin of the 39, 23 and 17 percent figures that circulate on retailer pages. A blind, vehicle-controlled study in 15 women reported decreases in wrinkle length, wrinkle depth and overall skin roughness, with no significant placebo effect.^[1] It is not a PubMed-indexed paper. It appeared in a trade journal by the same Sederma author, and the CIR report summarizes it.^[1] The underlying study is not independently retrievable. Trade journals, supplier brochures and patents are not systematically indexed. Further manufacturer studies of similar quality therefore cannot be ruled out.

Every other human result attaches to a mixture. Matrixyl 3000, a Sederma trademark, is Pal-GHK combined with palmitoyl tetrapeptide-7. A split-face human study in 24 volunteers reported significant decreases in deep wrinkles and roughness, and increases in elasticity and tone.^[1] Those comparisons were within-arm against day 0 rather than contrasts between the two arms.^[1] The CIR report's cited source for it is a consumer skincare web page plus a corporate synopsis.^[1] A four-ingredient eye cream containing palmitoyl tripeptide-1 improved hydration, elasticity and ultrasound collagen density in a 12-week human trial.^[7] Its first affiliation is the cosmetic company's own research center, and it declares no conflict of interest.^[7] A 2026 human study in 30 women paired baicalin by day with palmitoyl tripeptide-1 by night, and its thesis is that timing is the active variable.^[8] Two of its affiliations are commercial cosmetic research companies, and it also declares no conflicts.^[8] None of these three tested Pal-GHK on its own.

The in vitro comparison of the ingredient and the blend

The CIR assessment carries an in vitro result on the matrix endpoints this ingredient is marketed for. Human fibroblasts were incubated with palmitoyl tripeptide-1 or with Matrixyl 3000.^[1] The report's narrative describes those fibroblasts as incubated in the presence of vitamin C, which its own data table omits.^[1] Vitamin C is a required cofactor for collagen hydroxylation, so the two descriptions of the experiment are not interchangeable. Palmitoyl tripeptide-1 produced no dose response for collagen 1 synthesis, or for de novo fibronectin and hyaluronic acid synthesis.^[1] The blend produced a dose response on all three endpoints.^[1] The blend was tested to a higher top concentration than the single ingredient.^[1] Both results come from the source the report names as a corporate synopsis and a consumer web page.^[1]

The same report separately records a strong collagen synthesis signal for palmitoyl tripeptide-1 in human fibroblasts in vitro.^[1] That positive result was obtained at a lower concentration than the highest one used in the dose-response experiment.^[1] The report carries both results on the same endpoint and does not reconcile them.^[1]

A 2019 systematic review of matrix-stimulating cosmetic peptides found 12 papers reporting 15 human studies in the whole literature.^[9] Six of the 15 used a placebo control and five were double-blinded, and the authors called for better controlled trials.^[9] A 2021 review of 88 marketed sensitive-skin cosmetics, which included palmitoyl oligopeptide, concluded that the available data sit mostly in patents and supplier brochures rather than randomized placebo-controlled studies.^[10] A 2025 independent review of topically applied GHK noted a surprising absence of clinical studies of GHK-Cu and Pal-GHK.^[11] On the basis of cellular studies, the same review concluded that both are effective and relatively skin permeable.^[11] It went on to propose permeation enhancement methods to increase their skin permeability further.^[11]

The only randomized, independent trial of anything Matrixyl-branded returned a negative result. Twenty breast cancer patients undergoing radiotherapy were randomized to a cream containing original Matrixyl or to a dexpanthenol lotion.^[12] No differences in any toxicity measure were found between the groups.^[12] Mild itchiness and sporadic efflorescences were more frequent with the Matrixyl cream, and adverse events occurred only in that arm.^[12] The authors concluded that higher costs and skin-marking problems prevented a general recommendation.^[12] That cream contained pal-KTTKS alongside two other actives, not Pal-GHK.

Preclinical work and safety limits

The newest Pal-GHK record is a 2026 study in vitro and in mice, testing Pal-GHK with EGCG and biotin in a stress-induced alopecia model.^[13] One author affiliation is a commercial biotechnology company, and the paper declares no conflicts of interest.^[13] The design does not isolate Pal-GHK.

Two safety findings in the record concern the parent molecule rather than Pal-GHK. Intraperitoneal injections of unmodified GHK in mice and rats stimulated hepatocyte mitotic activity and suppressed immune reactivity, and the suppression was dose-dependent.^[14] The CIR assessment separately records that unmodified GHK stimulated growth of human KB and HeLa tumor cell lines in vitro, while not stimulating normal WI-38 cells.^[1] Neither finding concerns palmitoylated, topically applied Pal-GHK.

Pal-GHK is a cosmetic ingredient, and it is not a component of any FDA-approved drug. The CIR Panel is funded by the Personal Care Products Council, the industry trade association, so its assessment is not an independent regulator's finding. Its safe conclusion is bounded to typical cosmetic peptide use, which the report describes as 1 to 30 ppm, with under 10 ppm customary.^[1] The surveyed maximum concentration for palmitoyl tripeptide-1 was 0.001 percent.^[1] The report also states that carcinogenicity and reproductive and developmental toxicity data for these ingredients were not found in the published literature.^[1] That safety record therefore speaks only to topical use at trace concentrations. Nothing in it addresses safety at research-vial quantities or by any non-topical route.^[1]

Conclusion

Pal-GHK is a distinct molecule from GHK-Cu, and it does not inherit that peptide's evidence base. Its human record, as far as it can be traced, is two small manufacturer-run studies of the ingredient alone, neither independently replicated, plus several studies of mixtures. ClinicalTrials.gov lists no registered trial of it. In the CIR report's in vitro comparison of the ingredient against the blend, the ingredient showed no dose response on any of the three matrix endpoints.

Frequently Asked Questions

Is Pal-GHK the same as GHK-Cu? No. Pal-GHK is palmitoyl tripeptide-1, C30H54N6O5, and its formula contains no copper. GHK-Cu is copper tripeptide-1, C14H21CuN6O4-, which contains copper and is not palmitoylated. Nothing in the GHK-Cu record is evidence about Pal-GHK.

Has Pal-GHK on its own been tested in a controlled human study? Two small vehicle-controlled human studies of the ingredient alone can be traced, and both come from Sederma.^[1][3] Neither has been independently replicated, and one appeared in a trade journal rather than an indexed one.^[1] Trade journals, supplier brochures and patents are not systematically indexed, so further manufacturer studies of similar quality cannot be ruled out. ClinicalTrials.gov lists no registered trial of palmitoyl tripeptide-1.

Do Matrixyl 3000 results apply to Pal-GHK? No, because Matrixyl 3000 is Pal-GHK combined with palmitoyl tetrapeptide-7. In the CIR report's in vitro comparison of both, the blend produced a dose response for collagen 1, fibronectin and hyaluronic acid synthesis.^[1] Palmitoyl tripeptide-1 showed no dose response on any of the three endpoints.^[1]

Is Pal-GHK an FDA-approved drug? No. It is a cosmetic ingredient, and it is not a component of any FDA-approved drug. The CIR Expert Panel's 2014 safe-as-used conclusion is an industry-funded safety assessment rather than a regulatory approval.^[1]

References

1. 1

   Cosmetic Ingredient Review Expert Panel. Safety Assessment of Tripeptide-1, Hexapeptide-12, their Metal Salts and Fatty Acyl Derivatives, and Palmitoyl Tetrapeptide-7 as Used in Cosmetics. Final Report, 30 June 2014. https://www.cir-safety.org/sites/default/files/tripep062014final.pdf (industry expert-panel safety assessment, no PMID or DOI)
2. 2

   Hong M, et al. Palmitoyl copper peptide and acetyl tyrosine complex enhances melanin production in both A375 and B16 cell lines. Biochem Biophys Res Commun. 2025. PMID 39632290.
3. 3

   Lintner K, Peschard O. Biologically active peptides: from a laboratory bench curiosity to a functional skin care product. Int J Cosmet Sci. 2000. PMID 18503476.
4. 4

   Castelletto V, et al. Self-assembly of palmitoyl lipopeptides used in skin care products. Langmuir. 2013. PMID 23822110.
5. 5

   Jones RR, et al. Collagen stimulating effect of peptide amphiphile C16-KTTKS on human fibroblasts. Mol Pharm. 2013. PMID 23320752.
6. 6

   Talalaj U, et al. The Effects of a Novel Series of KTTKS Analogues on Cytotoxicity and Proteolytic Activity. Molecules. 2019. PMID 31618846.
7. 7

   Yang F, et al. Comprehensive evaluation of the efficacy and safety of a new multi-component anti-aging topical eye cream. Skin Res Technol. 2024. PMID 38932444.
8. 8

   Wang C, et al. Targeting Circadian Rhythm for the Regulation of Skin Collagen Metabolism. J Cosmet Dermatol. 2026. PMID 41527525.
9. 9

   Michalek IM, et al. Peptides stimulating synthesis of extracellular matrix used in anti-ageing cosmetics: Are they clinically tested? A systematic review of the literature. Australas J Dermatol. 2019. PMID 30941744.
10. 10

    Resende DISP, et al. Usage of Synthetic Peptides in Cosmetics for Sensitive Skin. Pharmaceuticals (Basel). 2021. PMID 34451799.
11. 11

    Mortazavi SM, et al. Topically applied GHK as an anti-wrinkle peptide: Advantages, problems and prospective. Bioimpacts. 2025. PMID 39963574.
12. 12

    Roper B, et al. Theta-Cream versus Bepanthol lotion in breast cancer patients under radiotherapy. A new prophylactic agent in skin care? Strahlenther Onkol. 2004. PMID 15127162.
13. 13

    Zheng X, et al. EGCG-Biotin-Pal-GHK composition modulates TGF-beta and BMP pathways in scalp microenvironment for treating stress-induced alopecia. Eur J Pharmacol. 2026. PMID 42575238.
14. 14

    Smakhtin MY, et al. Tripeptide Gly-His-Lys is a hepatotropic immunosuppressor. Bull Exp Biol Med. 2002. PMID 12447473.