Pal-GHK: what palmitoyl tripeptide-1 is, what the research shows and what is unknown

Pal-GHK is a chemically modified version of GHK, a tripeptide made of glycine, histidine and lysine. GHK was found in human serum in 1973 by Loren Pickart and M. M. Thaler, who reported that it prolonged the survival of normal liver cells in culture ^[1], and it later became famous as the peptide half of GHK-Cu, the copper complex that stimulates collagen synthesis in fibroblasts ^[2]. Pal-GHK takes the same three amino acids and attaches a 16-carbon palmitic acid chain to the N-terminal glycine. Its cosmetic ingredient name is palmitoyl tripeptide-1; older labels call it palmitoyl oligopeptide, and stores write it PAL-GHK, Pal GHK peptide or palmitoyl-GHK.

The reason for the fatty chain was set out in a 2000 paper from Sederma, the French company that makes most of the palmitoyl peptides used in cosmetics. Small hydrophilic peptides are fragile, expensive and do not cross the skin; attaching a long-chain fatty acid, the authors reported, improves skin penetration, specific activity and cost-effectiveness ^[3]. The same logic produced Matrixyl, which is palmitoyl pentapeptide-4. Pal-GHK is sold by Sederma mainly as part of Matrixyl 3000, a blend of palmitoyl tripeptide-1 and palmitoyl tetrapeptide-7 (Pal-GQPR), so most of the human data on Pal-GHK are data on that blend.

Reviews of topical peptides class GHK-Cu as a carrier peptide, delivering copper, and the palmitoyl peptides as signal peptides that prompt fibroblasts to make matrix ^[12]. Pal-GHK sits between the two: it keeps the GHK sequence but, as explained below, the palmitoyl group changes how it can hold copper. Research peptide stores list it in lyophilised vials beside GHK-Cu, AHK-Cu, Pal-AHK and SNAP-8. For how that market works, see what research peptides are.

The mechanism claimed for Pal-GHK is borrowed from GHK. In 1988 Maquart, Pickart and colleagues showed that GHK-Cu stimulated collagen synthesis in fibroblast cultures, beginning at concentrations between 10⁻¹² and 10⁻¹¹ M and peaking at 10⁻⁹ M, and noted that the GHK sequence occurs within the alpha-2 chain of type I collagen, suggesting it is released at wound sites as a repair signal ^[2]. A 2025 review of topically applied GHK summarises decades of cell work showing effects on collagen and glycosaminoglycan synthesis, nerve outgrowth and blood-vessel growth, and concludes that on the basis of cellular studies GHK can be considered an anti-wrinkle ingredient ^[4].

Palmitoylation is meant to solve the delivery problem. The same review notes that both metal complexation and attaching a hydrophobic group increase the skin permeability of GHK ^[4]. Physical chemistry studies of fatty-acid GHK derivatives show why: hexanoyl, decanoyl and myristoyl versions of GHK bind strongly to phospholipid bilayers, with the fatty chain inserting into the membrane and the peptide protruding from the surface ^[7]. That is the behaviour expected of Pal-GHK, which has an even longer chain. Whether it then leaves the membrane, reaches the dermis and reaches fibroblasts at a concentration in the nanomolar range where GHK acts has not been shown for Pal-GHK; for the related Pal-KTTKS, mouse skin studies found the lipopeptide in the dermis but at a small fraction of the applied dose ^[13].

One point of chemistry is worth stating clearly because product names blur it. GHK binds copper(II) through its N-terminal amine, a backbone amide nitrogen and the histidine imidazole ring ^[9]. In Pal-GHK the N-terminal amine is acylated by the palmitoyl group, so the copper-binding site is altered. Products described as palmitoyl copper peptide or Pal-GHK-Cu exist and have been used in cell studies ^[8], but they are not simply GHK-Cu with a fatty tail, and their copper chemistry is not described in the published literature. A Pal-GHK vial and a GHK-Cu vial are different materials.

The Pal-GHK benefits claimed by sellers are smoother, firmer skin with fewer wrinkles, faster repair, fuller lips, and, more recently, hair growth. Searches for Pal-GHK vs GHK-Cu are common, since the two names look alike. Here is what the published record supports for each.

Wrinkles and skin structure: the relevant human studies used blends. A 2015 study by Sederma researchers used a combination of imaging methods, including in vivo reflectance confocal microscopy and ultrasound, to look at the dermal matrix and the junction between epidermis and dermis in aged skin; a blend of palmitoyl oligopeptide (Pal-GHK) and palmitoyl tetrapeptide-7, the Matrixyl 3000 combination, reduced the thickness of the subepidermal low-echogenic band, a marker of sun-damaged dermis, improved its density, and improved matrix structure compared with placebo ^[5]. A 2024 12-week open study of an eye cream containing palmitoyl tripeptide-1, palmitoyl tetrapeptide-7, a yeast/rice ferment and N-acetylneuraminic acid reported improvements in hydration, elasticity and ultrasound collagen density, with participants and dermatologists noting fewer fine lines by week eight; there was no placebo and four actives, so nothing can be attributed to Pal-GHK ^[6]. The 2025 GHK review’s summary is blunt: although GHK-Cu and Pal-GHK are widely used in anti-wrinkle products, there is a surprising absence of clinical studies using them ^[4].

Lips: a 2009 open-label study of a two-step lip treatment, one part of which contained a palmitoyl-glycyl-histidyl-lysine complex alongside growth factors, hyaluronic acid and emollients, reported significant improvements in lip dryness, texture and fullness in 32 women over four weeks, with no adverse events ^[10]. The study had no control group and the product had many ingredients.

Pigmentation: a 2025 cell study found that a complex of palmitoyl copper peptide and acetyl tyrosine increased melanin production in human and mouse melanoma cell lines, through tyrosinase and related genes ^[8]. That is an in vitro result in cancer cell lines, aimed at tanning or grey-hair products, and it is a reminder that a copper form of Pal-GHK may do things the plain peptide does not.

Pal-GHK hair growth claims rest on one paper. A 2026 mouse study combined EGCG, biotin and Pal-GHK in a stress-induced hair-loss model and reported reduced follicular fibrosis, improved follicle morphology and regrowth, with changes in TGF-β and BMP signalling ^[11]. Pal-GHK was one of three components, the model was chronic stress in mice rather than pattern hair loss, and there is no human study. For the hair-growth field more broadly, see peptides for hair growth.

Pal-GHK vs GHK-Cu: no study has compared them. GHK-Cu has small human trials of topical products and decades of cell and animal work, described on the GHK-Cu page; Pal-GHK has better theoretical skin penetration and almost no data of its own. Neither has any published human data by injection.

There is no published human study of Pal-GHK as a single ingredient and no registered clinical trial as of September 2026. The human data are the placebo-controlled imaging study of the Matrixyl 3000 blend ^[5], the open eye-cream study ^[6] and the open lip study ^[10], each with several actives and each linked to the company selling the product. Percentages quoted on retail pages for palmitoyl tripeptide-1, such as wrinkle depth reductions after two months, come from the ingredient supplier’s own test reports rather than from peer-reviewed publications.

The blend studies measured changes at four weeks for lips ^[10], and at eight to twelve weeks for wrinkles, hydration and collagen density ^[6]. Since the proposed mechanism is increased collagen and matrix production by fibroblasts, a slow process, one to three months of daily topical use is the timescale the studies suggest, and there are no data on what happens after stopping.

Pal-GHK dosage in the literature means a concentration in a cream, and the published studies do not state the peptide percentage in their test products; commercial Matrixyl 3000 is a dilute solution used at a few percent of the finished product, which puts palmitoyl tripeptide-1 in the parts-per-million range in a cream. In cell culture, the parent GHK-Cu acts between 10⁻¹² and 10⁻⁹ M ^[2]. None of these figures are recommendations.

No study has given Pal-GHK by injection, by mouth or under the skin, so there is no dose to report for the vials research stores sell, which typically contain tens of milligrams, enough to formulate a great deal of cream. The peptide calculator converts vial contents to a solution concentration for laboratory or topical use; it cannot supply a dose that no study has established.

Every published use of Pal-GHK is topical: creams, serums, eye and lip products, generally in oil-in-water emulsions where the palmitoyl chain sits in the oil phase. The palmitoyl group makes the molecule surfactant-like; fatty-acid GHK derivatives insert into lipid membranes ^[7], and the related Pal-KTTKS forms micelles and nanotapes in water above a low threshold concentration. Microneedle pre-treatment substantially increases the delivery of small cosmetic peptides into excised human skin ^[14], and patch formats are increasingly used for that reason.

Research peptide suppliers sell Pal-GHK as lyophilised powder, often in the same 5 mg to 50 mg vials as injectable peptides. Dissolving it into a topical base at least matches the studied route. Injection has never been studied for Pal-GHK in any species. The chemistry gives a specific reason for caution: the myristoyl derivative of GHK, with a 14-carbon chain, caused complete lysis of red blood cells at 2.5 × 10⁻⁴ M in one study, while the shorter hexanoyl and decanoyl versions caused only 10% haemolysis at twice that concentration ^[7]. Pal-GHK carries a longer 16-carbon chain. Membrane-active lipopeptides are formulated for skin surfaces, not bloodstreams.

In the topical product studies, Pal-GHK side effects were not reported: the eye cream study described a high safety profile over 12 weeks ^[6], the lip study reported no adverse events ^[10], and Matrixyl 3000 has been in cosmetic products for two decades without a notable safety signal. GHK itself is a natural human peptide present in plasma, saliva and urine, which makes the peptide portion about as low-risk as a cosmetic ingredient can be.

That record applies to trace amounts on the skin. For injection there are no data, and the palmitoyl chain, not the peptide, is the concern: acylated GHK derivatives are haemolytic at high concentration ^[7]. Two further points apply to any GHK product. First, GHK is a growth-promoting signal; the original 1973 paper reported that it prolonged survival of normal liver cells but also stimulated growth of liver tumour cells in culture ^[1], an observation that has never been followed up in people but is a reason not to assume that a repair peptide is indifferent to what it repairs. Second, a copper-containing version, if that is what a vial contains, adds the considerations that apply to GHK-Cu.

A 2026 paper on a safety-evaluation framework for cosmetic peptides notes that the industry now substantiates safety through bioinformatic screening for toxin and allergen similarity rather than animal studies ^[15]. A fragment of human collagen with a fatty tail raises no such flags, but that framework addresses cosmetic use only.

Palmitoyl tripeptide-1 is a permitted cosmetic ingredient in the UK, EU and US, used within the ordinary rules for cosmetics, under which the marketing company must hold safety data but need not prove efficacy. It is not an approved medicine anywhere, has not been the subject of any FDA compounding decision, and is not on the WADA Prohibited List. Sold as a research chemical in a vial, it falls under the general rules for research peptides; see our legal status overview, with pages for the UK and the US.

Lyophilised Pal-GHK is stored cold, dry and away from light; see how to store peptides. Because of the palmitoyl chain it is poorly soluble in plain water and tends to form a cloudy dispersion; cosmetic formulators dissolve it in glycols or oils, or into the oil phase of an emulsion. For laboratory use, bacteriostatic water is the usual starting solvent, but expect the material to behave like a surfactant rather than dissolving cleanly. Solutions should be refrigerated and used within a limited period, since skin proteases and ordinary hydrolysis degrade small peptides.

Pal-GHK is a short peptide and inexpensive to synthesise; price per milligram is the useful comparison, since a cream needs only parts per million. Compare Pal-GHK prices across suppliers, and check listings in the UK and the US; peptide prices explained covers how stores set prices.

A certificate of analysis for Pal-GHK should show a measured mass close to 579 g/mol and an HPLC purity figure. A mass near 340 g/mol would indicate plain GHK without the palmitoyl group; a copper-containing product should be described as such and should report copper content, which most COAs do not. Because Sederma sells Pal-GHK mainly as the Matrixyl 3000 blend, check whether a listing is the single peptide or the blend with palmitoyl tetrapeptide-7. Our guides to reading a COA and third-party testing explain what to look for, and our list of third-party tested suppliers shows which stores publish independent results. For other peptides sold for skin, see peptides for skin.