Compound reference
GHK-Cu
Also known as Copper Tripeptide-1, Gly-His-Lys Copper
GHK-Cu (copper tripeptide-1) is an endogenous copper-binding peptide with decades of mechanism research and genuine topical wound-healing evidence — including a diabetic-ulcer RCT. Its injectable "biohack" use, however, far outruns the human data.
- CAS
- 89030-95-5
- Formula
- C₁₄H₂₄N₆O₄ (GHK); ≈C₁₄H₂₂CuN₆O₄ (GHK–Cu)
- Molar mass
- 340.4 g/mol (GHK); ≈402 g/mol (GHK–Cu complex)
- Sequence
- Glycyl-L-histidyl-L-lysine (Gly-His-Lys), 1:1 complex with Cu(II)
Topical/cosmetic research compound; not an approved injectable drug.
Mode of action
GHK-Cu is unusual among research peptides in that it is genuinely endogenous: the tripeptide glycyl-L-histidyl-L-lysine (GHK) circulates in human plasma, and Loren Pickart first isolated it in 1973 as an activity in human albumin that made aged liver tissue behave like young tissue. The sequence corresponds to a fragment of the α2(I) chain of type I collagen, and the working model is that proteases liberate GHK from the matrix at sites of injury, where it binds copper(II) with high affinity to form the active complex GHK-Cu.
Its action has two layers. The first is copper handling — GHK-Cu is a copper shuttle, coordinating Cu(II) in a square-planar geometry (histidine imidazole nitrogen, the glycine α-amino group, and the deprotonated Gly-His amide nitrogen) and delivering it to copper-dependent enzymes such as lysyl oxidase and superoxide dismutase. The second, and harder to pin down, is signaling: gene-profiling work using the Broad Institute's Connectivity Map reports that GHK shifts expression of roughly a third of human genes by 50% or more — upregulating collagen, elastin and glycosaminoglycan synthesis, antioxidant and DNA-repair clusters, while suppressing others such as the fibrinogen β-chain. Pickart's reviews frame GHK as a systemic "injury-response signal" that resets pathological expression toward health. That framing is mechanistically attractive but should be read with care: the authors themselves note that broad gene-profiling data cannot yet be reliably translated into predicted tissue-level outcomes.
Main intended effect
Skin repair and anti-aging — stimulating collagen, elastin and glycosaminoglycan synthesis to produce firmer, denser, less-wrinkled skin — and acceleration of wound healing.
Areas of interest
The dominant, evidence-backed use is topical cosmetic dermatology, where GHK-Cu is a long-standing "copper peptide" anti-aging active. Wound healing is the second established interest (diabetic ulcers, acute cutaneous wounds), with hair (follicle stimulation, eyebrow density) a smaller strand. More recently it has been adopted as an injectable "biohack" and putative orthobiologic for soft-tissue and joint repair — a use that runs well ahead of its evidence. Because endogenous GHK declines with age (averaging roughly 200 ng/mL at age 20 and falling to about 80 ng/mL by 60), it is also studied as a candidate systemic repair signal.
Evidence for intended effects
The honest picture is split by route. Topical and wound-healing evidence is the strongest: a multicenter, randomized, evaluator-blinded, placebo-controlled trial (Mulder, 1994) found that a topical GHK-Cu gel markedly accelerated closure of diabetic neuropathic ulcers (median closure ~98.5% vs ~60.8% for vehicle) with lower post-debridement infection rates — a genuine RCT, not a marketing study. A current registered Phase 2 trial (CuHeal, NCT07437586) is now testing a topical GHK-Cu gel on standardized punch-biopsy wounds, though no results are posted yet. Cosmetic wrinkle endpoints are supported mostly by smaller split-face work (e.g. Badenhorst, 2016) that is industry-funded and published in a low-tier journal; the mechanistic literature is deep and consistent (Maquart's 1988 collagen-synthesis work and the gene-data reviews), but robust, independent cosmetic-endpoint RCTs remain thin.
The weakest link is precisely where the current hype concentrates: systemic and injectable GHK-Cu has essentially no human efficacy trials. The "biohack" injectable use rests entirely on topical and preclinical extrapolation, and sports-medicine reviews caution against routine musculoskeletal use on exactly those grounds.
| Strand | What exists | Tier |
|---|---|---|
| Topical wound healing | Diabetic-ulcer RCT (1994) + registered Phase 2 (CuHeal) | Controlled human (topical) |
| Topical cosmetic / anti-aging | Small split-face trials + decades of use; few independent RCTs | Limited human |
| Mechanism / ECM / gene data | Collagen, GAG, MMP/TIMP, Connectivity Map studies | Strong preclinical |
| Injectable / systemic | No human efficacy trials | Extrapolation only |
Studied amounts (literature dosing context)
Topical study amounts are concrete: the Mulder ulcer trial metered the gel to deliver 0, 2, or 6 mg of GHK-Cu per cm² of ulcer once daily; cosmetic serums are typically low-percentage formulations, and the CuHeal trial uses a 0.1% gel. Proposed systemic doses are extrapolations only — Pickart has estimated a ~35 µg systemic dose scaled from animal data, and a bone-healing study used ~140 µg per injection in combination with other peptides — none of which is validated by a dose-finding human trial. There is no approved injectable dose. These are study and estimation figures, not dosing guidance.
Safety and regulatory status
For topical use the safety record is reassuring: the Cosmetic Ingredient Review Expert Panel assessed Copper Tripeptide-1 (GHK-Cu) and related ingredients as safe as used in cosmetics, consistent with decades of topical use and only rare reports of local irritation. That assessment applies strictly to topical cosmetic application and explicitly does not cover injectable or systemic routes.
Injectable use is a different matter. The FDA treats compounded injectable GHK-Cu as an unapproved new drug, citing the absence of adequate human safety data and concerns about impurities and characterization in compounded bulk preparations, and its 503A bulk-substance review has handled GHK-Cu in a route-specific way (with injectable formulations under the more cautious track). There is no approved injectable GHK-Cu product in any jurisdiction, and systemic copper loading is a theoretical concern that has not been characterized in humans.
Sources
The human tri-peptide GHK and tissue remodeling
Early comprehensive review by Pickart in the Journal of Biomaterials Science, Polymer Edition characterizing the tissue-remodeling biology of the human tripeptide GHK and its copper complex GHK-Cu. The review describes four interconnected remodeling actions: chemoattraction of macrophages, mast cells, and capillary cells to sites of injury; broad anti-inflammatory activity through suppression of free radicals, thromboxane, oxidizing iron release, and pro-inflammatory cytokines alongside enhancement of antioxidant enzymes; stimulation of protein synthesis including collagen, elastin, growth factors (VEGF, FGF-2, NGF), and neurotrophins; and promotion of fibroblast and keratinocyte proliferation, angiogenesis, nerve outgrowth, and hair follicle development. Applied clinical benefits reported include improved aged skin appearance, accelerated wound and ulcer healing, and tissue protection from chemical injury. The review notes these findings are beginning to define the complex biochemical processes regulating tissue remodeling, with the understanding that most evidence at that time derived from in vitro and animal studies rather than controlled clinical trials.
GHK Peptide as a Natural Modulator of Multiple Cellular Pathways in Skin Regeneration
Narrative review by Pickart, Vasquez-Soltero, and Margolina in BioMed Research International synthesizing biochemical, in vitro, and in vivo evidence for GHK and its copper complex GHK-Cu as modulators of skin regeneration. The review describes stimulation of fibroblast activity, collagen and glycosaminoglycan synthesis, balanced modulation of matrix metalloproteinases and their inhibitors, chemoattraction of immune and endothelial cells to injury sites, and accelerated wound healing across skin, hair follicles, gastrointestinal tract, and bone. It also notes that endogenous GHK declines with age, framing GHK-Cu as the replacement of a lost repair signal. Most supporting evidence derives from preclinical and in vitro systems, and the authors note that controlled human clinical data remain limited in scope.
Regenerative and protective actions of the GHK-Cu peptide in the light of the new gene data
Literature review by Pickart and Margolina in the International Journal of Molecular Sciences integrating older biochemical evidence with Connectivity Map genomic data to characterize GHK-Cu's regenerative and protective mechanisms. Analysis of expression profiles found GHK modulates approximately 31.2% of human genes by ≥50%, stimulating 59% of those genes and suppressing 41%; key upregulated clusters included 408 neuronal genes, 41 ubiquitin-proteasome genes, and 84 DNA repair-related genes, while the fibrinogen beta-chain gene was strongly downregulated (−475%) and metastatic gene signatures were suppressed. At the tissue level, GHK-Cu promotes blood vessel and nerve outgrowth, increases collagen, elastin, and glycosaminoglycan synthesis, supports dermal fibroblast function and epidermal stemness, and has demonstrated repair capacity across skin, lung connective tissue, bone, liver, and stomach lining. The authors conclude that copper-binding alone cannot account for GHK-Cu's breadth of action and propose a model in which GHK acts as a systemic injury-response signal that orchestrates multiple protective pathways simultaneously, though they acknowledge that correlating broad genomic effects with definitive tissue-level outcomes requires substantially more experimental work.
Stimulation of collagen synthesis in fibroblast cultures by the tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu2+
Maquart and colleagues demonstrated in cultured fibroblasts that the tripeptide-copper complex GHK-Cu dose-dependently stimulates collagen synthesis, with a response beginning between 10−12 and 10−11 M and reaching maximal stimulation near 10−9 M. The effect was independent of any change in cell number, indicating direct metabolic activation rather than proliferation-driven output. The authors proposed that GHK is physiologically liberated by proteases from the alpha2(I) chain of type I collagen at wound sites, suggesting an in situ repair role. The source fibroblast line (human versus animal) is not specified in the abstract, and all findings are from in vitro cell culture; in vivo wound-healing translation requires separate validation.
GHK and DNA: resetting the human genome to health
Narrative review by Pickart, Vasquez-Soltero, and Margolina in BioMed Research International examining GHK's capacity to modify gene expression in aged and diseased cell datasets. Gene profiling analysis found that GHK increased or decreased expression by more than 50% in 32.1% of human genes; in cancer cell lines from neuroblastoma, histiocytic lymphoma, and breast cancer, GHK reactivated apoptotic signaling and inhibited growth at 1–10 nanomolar concentrations, while in COPD patient fibroblasts it restored collagen contraction and remodeling through TGF-beta pathway activation. Additional pathway effects included strong suppression of fibrinogen beta-chain gene expression (−475%), upregulation of 41 ubiquitin-proteasome genes, stimulation of 47 DNA repair genes, and upregulation of 14 antioxidant defense genes with concurrent suppression of 2 prooxidant genes. The authors propose GHK represents a practical step toward simultaneous genomic resetting across hundreds of aging-related genes, while explicitly acknowledging that gene profiling data cannot yet be reliably translated into predicted biological effects—a limitation that constrains therapeutic interpretation.
The potential of GHK as an anti-aging peptide
Narrative review by Dou, Lee, Zhu, Morton, and Ladiges (University of Washington) in Aging Pathobiology and Therapeutics examining GHK as a candidate systemic anti-aging intervention. The review highlights that circulating GHK levels decline substantially with age—averaging approximately 200 ng/ml at age 20 but falling to roughly 80 ng/ml by age 60—and proposes this decline as a contributing factor to reduced tissue repair capacity. GHK-Cu chelate demonstrates anti-inflammatory and antioxidant effects in experimental systems, and preliminary mouse studies suggest GHK can partially reverse cognitive impairment in aged animals through anti-inflammatory and epigenetic mechanisms. The authors conclude the evidence provides a rationale to further investigate GHK in preclinical aging models and eventually in clinical aging studies, while characterizing the cognitive findings as preliminary observations requiring rigorous validation before therapeutic claims can be made.
Enhanced healing of ulcers in patients with diabetes by topical treatment with glycyl-L-histidyl-L-lysine copper
Multicenter, randomized, evaluator-blinded, placebo-controlled clinical study (Mulder and colleagues, Wound Repair Regen 1994) of topical glycyl-l-histidyl-l-lysine copper complex (lamin Gel) applied with standardized wound care including sharp debridement and pressure-relieving footwear in patients with diabetic neuropathic plantar ulcers. The active treatment arm achieved a median area closure of 98.5% versus 60.8% for vehicle (p < 0.05), with a rate of closure approximately three times faster. In the pre-specified subgroup of larger ulcers (>100 mm²), median closure was 89.2% with lamin Gel versus −10.3% for vehicle (p < 0.01). Infection rates immediately after debridement were significantly lower with active treatment: 7% versus 34% (p < 0.05). The authors concluded that topical GHK-Cu significantly enhances diabetic ulcer healing, particularly when initiated promptly after debridement and in larger lesions.
Topical GHK-Cu Gel for Acute Skin Wound Healing (CuHeal, Phase 2)
Registered Phase 2, randomized, double-blind, vehicle-controlled, split-wound study (NCT07437586, CuHeal) evaluating 0.1% topical GHK-Cu gel applied to standardized punch-biopsy wounds in approximately 60 healthy adult volunteers. The primary endpoint is rate of re-epithelialization assessed over three weeks, with a secondary scar-quality follow-up at twelve weeks; the split-wound design controls for inter-subject variability by placing active and vehicle treatments on paired wounds in the same individual. This is the first registered controlled Phase 2 trial of a topical GHK-Cu formulation for acute wound healing in humans. As of early 2026, the trial is registered; no results have been posted and the study represents prospective rather than established evidence.
Effects of GHK-Cu on MMP and TIMP Expression, Collagen and Elastin Production, and Facial Wrinkle Parameters
Combined mechanistic and clinical study (Badenhorst and colleagues, J Aging Sci 2016) pairing a human dermal-fibroblast in-vitro experiment with an 8-week randomized, double-blind, split-face controlled trial. In vitro, GHK-Cu at 0.01, 1, and 100 nM increased collagen and alpha-elastin production in a concentration-dependent manner with corresponding MMP/TIMP modulation. The clinical arm enrolled 40 women and compared a GHK-Cu nano-carrier serum against Matrixyl 3000 and vehicle, assessing facial wrinkle volume and depth by optical profilometry. The GHK-Cu serum arm reported greater reductions in wrinkle volume and depth than the comparator arms. As a split-face industry-funded cosmetic trial published in an open-access journal, independent replication is needed to establish robust clinical conclusions.
Topical Peptide Treatments with Effective Anti-Aging Results
Narrative review by Schagen in Cosmetics (MDPI) systematically surveying topical cosmeceutical peptides organized into four functional classes: signal peptides (which stimulate matrix protein synthesis), carrier peptides (which deliver trace elements, including Cu-GHK that chelates copper to support collagen and glycosaminoglycan production), neurotransmitter-inhibiting peptides (which reduce facial muscle contraction), and enzyme-inhibiting peptides (which block collagenase and elastase activity). For Cu-GHK specifically, the review cites clinical evidence from collagen biopsy studies and photoaging assessments demonstrating measurable improvements in dermal structure and skin surface quality. The review provides a framework for understanding the mechanistic heterogeneity among cosmeceutical peptides and contextualizes Cu-GHK within the carrier class as a validated skin active with multiple supporting clinical observations. The author notes that while clinical evidence for several peptide classes is accumulating, study sizes and methodological consistency remain constraints on definitive efficacy conclusions across the cosmeceutical peptide field.
Safety Assessment of Tripeptide-1, Hexapeptide-12, Their Metal Salts and Fatty Acyl Derivatives, and Palmitoyl Tetrapeptide-7 as Used in Cosmetics
Safety assessment published in the International Journal of Toxicology by the Cosmetic Ingredient Review (CIR) Expert Panel, evaluating Tripeptide-1 (GHK), Copper Tripeptide-1 (GHK-Cu), their metal salts, fatty acyl derivatives, and palmitoyl tetrapeptide-7 as used in cosmetic formulations. The panel reviewed available toxicological, dermal penetration, and clinical data and concluded that these ingredients are safe under current practices and concentrations of cosmetic use. The assessment applies exclusively to topical cosmetic applications and does not address injectable or systemic routes of administration. This CIR determination does not constitute FDA approval for any therapeutic indication and does not speak to the regulatory status of GHK-Cu as a bulk drug substance for compounding.
FDA Statement on Copper Peptides (GHK-Cu) in Injectable Products
FDA regulatory page (March 2024) addressing the status of copper peptides, including GHK-Cu (glycine-histidine-lysine copper), in injectable compounded products. The FDA classifies injectable GHK-Cu formulations as unapproved new drugs, citing the absence of adequate human safety data and concerns about impurities and characterization in compounded bulk preparations. Topical cosmetic use of GHK-Cu is not regulated under the drug framework and is not addressed by this FDA action. The FDA's position is that injectable copper peptide products lack the clinical evidence and quality standards required to support safe human use, and compounding of these substances for injection is a regulatory violation.
https://www.fda.gov/drugs/human-drug-compounding/copper-peptides
FDA 503A Bulk Drug Substances Update (May 2026): Non-Injectable GHK-Cu Returned to Category 1
FDA's updated 503A Bulk Drug Substances list, current as of May 14, 2026, which tracks substances nominated for use in compounding under Section 503A of the Federal Food, Drug, and Cosmetic Act. Following a nominator clarification, non-injectable GHK-Cu (Copper Tripeptide-1) was returned to Category 1 for evaluation after the nominator confirmed it had withdrawn only the injectable route nomination. Injectable GHK-Cu remains subject to the significant safety-risk discussion applicable to Category 2 substances. FDA has indicated it intends to consult the Pharmacy Compounding Advisory Committee (PCAC) on GHK-Cu by the end of February 2027. This route-specific bifurcation means the regulatory status of GHK-Cu differs depending on the intended route of administration, and neither placement constitutes approval for therapeutic use.
Safety and Efficacy of Approved and Unapproved Peptide Therapies for Musculoskeletal Injuries and Athletic Performance
Narrative review (Mendias and Awan, Sports Medicine, 2026) of approved and unapproved peptides marketed for musculoskeletal healing and athletic performance — including AOD-9604, CJC-1295, BPC-157, and others. For AOD-9604 it summarizes six randomized double-blind placebo-controlled human trials in over 900 patients that showed a favorable short-term safety profile but failed to demonstrate statistically significant dose-dependent weight loss versus placebo. The review's broader message is that many unapproved peptides carry potential for serious harm despite favorable tissue-repair or metabolic signals in animal models.