Raheleh Sarbaziha, MD, and David Goldberg, MD, JD, explain how copper peptide GHK-Cu bridges cosmetic science and true tissue regeneration across multiple clinical applications

Discovered in the early 19thcentury1, peptides have since evolved into a cornerstone of modern biomedical science. The copper tripeptide GHK-Cu was first identified and developed by Loren Pickart in 19732,3. This review explores the history, mechanisms, and expanding clinical applications of GHK-Cu — spanning its roles in aesthetic medicine (skin rejuvenation and hair restoration), wound repair, and regenerative medicine4–22.

What is a peptide

The term ‘peptides’ dates back to the early 19th century, when Emil Fischer and Franz Hofmeister first described their chemical structures1. In 1901, Fischer and Fourneau achieved the first peptide synthesis, identifying glycyl-glycine as the simplest peptide and later elucidating the structures of dipeptides, tripeptides, and polypeptides1. With ongoing biochemical advances, numerous natural and synthetic peptides have been developed. Among these, the copper-binding tripeptide glycyl-L-histidyl-L-lysine (GHK-Cu) was discovered by Loren Pickart in 1973, marking a key early milestone in regenerative and aesthetic peptide science2,3. However, it was not until the late 1980s that copper peptides began appearing in commercial skincare formulations1.

Topical cosmeceutical peptides are generally divided into four main functional categories: signal peptides, carrier peptides, neurotransmitter-inhibiting peptides, and enzyme-inhibiting peptides1. To achieve optimal biological activity, these peptides typically require a molecular weight under 500 Da, allowing effective penetration across the skin barrier1.

Carrier peptides, including copper- and manganese-binding tripeptides, play an essential role in stabilising and transporting trace elements critical for wound healing, enzymatic activation, and tissue regeneration1,5. Among them, GHK-Cu remains one of the most extensively studied. It acts as both a signal and a carrier peptide, supporting the extracellular matrix remodelling and being released at sites of inflammation or tissue injury, where it promotes collagen, elastin, proteoglycan, and glycosaminoglycan synthesis while exerting potent anti-inflammatory and antioxidant effects6–13.

Today, GHK-Cu is a cornerstone in cosmetic and dermatologic medicine, valued for its diverse applications in anti-ageing, anti-wrinkle, post-sun repair, skin hydration, and hair growth stimulation7–14.

Why is GHK attached to CU?

GHK (glycyl-L-histidyl-L-lysine) is a naturally occurring tripeptide first identified in human plasma, serum, saliva, and urine, where it was shown to promote cell growth and tissue repair2,3. The molecule has a strong affinity for copper(II) ions, forming the chelated complex GHK-Cu2,3.

Physiologically, plasma concentrations of GHK average about 200 ng/mL at age 20 but decline to approximately 80 ng/mL by age 60, a reduction that may reflect the body’s decreased regenerative capacity over time2,3,9. Studies have consistently shown that GHK-Cu supports skin and connective tissue health by enhancing cell proliferation, collagen production, and repair signalling7–14.

GHK-CU in aesthetics

For nearly four decades, GHK-Cu has been recognised for its ability to remodel tissue and enhance wound healing4,8–10. With copper being an essential trace mineral required for collagen and elastin formation, GHK-Cu serves as a natural carrier of copper ions, promoting connective-tissue repair and regeneration1,5,10,12.

Early work by Siméon and Wegrowski demonstrated that GHK-Cu stimulates the synthesis of glycosaminoglycans (GAGs), increases chondroitin sulfate accumulation, and enhances type I collagen production, leading to improved skin elasticity, clarity, and smoothness6,15. Clinically, these findings explain why GHK-Cu remains a key ingredient in many anti-ageing and reparative skin formulations1,4,7,8.

When GHK-Cu is combined with hyaluronic acid (HA), studies show a synergistic effect on collagen expression. The combination enhances collagen IV production by up to 25-fold in cell models and nearly 2-fold in human skin samples —especially at a 1:9 ratio of GHK-Cu to low-molecular-weight HA5,16. This synergy improves the dermal-epidermal junction (DEJ), contributing to firmer, more resilient skin4–6, 16.

Several placebo-controlled clinical and in vitro studies confirm GHK-Cu’s broad regenerative activity, including increased keratinocyte proliferation, improved firmness, elasticity, and barrier protection, and reduced rhytides, hyperpigmentation, and photodamage11. Topical application has been shown to stimulate procollagen synthesis more effectively than vitamin C, tretinoin, or melatonin11.

In a comparative trial, GHK-Cu increased collagen deposition in 70% of participants, compared with 50% with vitamin C and 40% with retinoic acid after 1 month of daily application7. Likewise, Leyden et al. found that 12 weeks of treatment with GHK-Cu cream improved skin density, thickness, elasticity, and moisture, producing smoother, more youthful-appearing skin4. A separate 12-week study involving 67 women confirmed that twice-daily GHK-Cu cream significantly thickened the epidermis and dermis and stimulated keratinocyte proliferation, consistent with visible improvements in texture and radiance7.

GHK-Cu and hair growth: What is AHK?

The copper tripeptide AHK-Cu (L-alanyl-L-histidyl-L-lysine-Cu²+) has demonstrated potent hair-regenerative activity in human models. Ex vivo studies show that AHK-Cu significantly stimulates human hair-follicle elongation at extremely low concentrations (10–¹² to 10–⁹ M), indicating high biological potency22. In cultured dermal papilla cells (DPCs) — the key regulators of the hair-growth cycle — AHK-Cu enhances cellular proliferation and metabolic activity, supporting stronger signalling to the surrounding follicular matrix22.

Importantly, AHK-Cu also shifts the apoptotic balance toward cell survival by increasing anti-apoptotic Bcl-2 expression, reducing pro-apoptotic Bax, and markedly lowering levels of cleaved caspase-3 and PARP fragmentation by 42.7% and 77.5%, respectively22. This coordinated reduction in apoptosis promotes healthier, more resilient DPCs capable of sustaining active anagen-phase growth.

Thus, AHK-Cu supports hair regeneration by stimulating DPC proliferation, enhancing follicle elongation, and protecting hair-regulatory cells from apoptosis, resulting in stronger, longer-growing hair follicles22.

GHK-Cu has also been shown to stimulate hair growth, supporting follicular enlargement, improving scalp collagen, and enhancing hair shaft strength — with outcomes comparable to those of topical minoxidil2,12,22. Patients using topical GHK-Cu post-hair transplant also demonstrated increased follicle density and healthier scalp structure2,22.

GHK-Cu and wound care

Researchers developed liposome-encapsulated GHK-Cu to evaluate its effects on cell proliferation and wound healing. In cell studies using human umbilical vein endothelial cells (HUVECs), GHK-Cu liposomes increased cell proliferation by approximately 33%, with more cells observed in the G1 (growth) phase and fewer in the G2 (division) phase, indicating enhanced cell-cycle activity. The treatment also upregulated the expression of VEGF, FGF-2, CDK4, and cyclin D1, all of which are key factors involved in cell growth and angiogenesis. In an animal model of scald injury, liposomal GHK-Cu promoted angiogenesis more effectively than free GHK-Cu, with stronger CD31 and Ki67 staining that reflected active vascular and cellular regeneration. Wound closure time was shortened to about 14 days post-injury, demonstrating faster recovery and improved tissue repair. Overall, the study found that GHK-Cu liposomes enhance cell proliferation, promote new blood-vessel formation, and accelerate wound healing, suggesting significant potential for use in regenerative and aesthetic medicine21.

Extensive research also shows that GHK-Cu accelerates wound closure, enhances wound contraction, improves skin-graft integration, and increases angiogenesis across multiple animal models8. At very low, non-toxic concentrations, the peptide stimulates collagen, glycosaminoglycans, and proteoglycans such as decorin, while modulating matrix metalloproteinases and their inhibitors to regulate extracellular-matrix remodelling during healing8. GHK-Cu additionally exerts meaningful anti-inflammatory and antioxidant actions by reducing cytokines such as TGF-β and TNF-β and increasing antioxidant enzyme activity.

Collectively, GHK-Cu promotes robust tissue repair through its ability to enhance extracellular-matrix production, stimulate angiogenesis, and regulate TIMP-1 and TIMP-2 during remodelling. Studies in rat models show dose-dependent increases in collagen, DNA, and glycosaminoglycan content at wound sites following GHK-Cu application5. The copper component also activates lysyl oxidase, the enzyme responsible for cross-linking collagen and elastin, thereby improving the tensile strength of newly formed tissue. Furthermore, microneedle-mediated delivery has demonstrated significantly enhanced dermal penetration, with up to 705 nanomoles of copper transported across treated skin, highlighting new opportunities for regenerative and aesthetic dermatology5.

Taken together, these findings position GHK-Cu as a powerful therapeutic that bridges aesthetic improvement and true regenerative wound healing, supporting scar remodelling, tissue renewal, and enhanced structural integrity5,8,21.

GHK-Cu and wellness

GHK-Cu has been shown to upregulate basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) in irradiated human dermal fibroblasts, both of which support angiogenesis and improve blood flow in damaged tissue2,3. It also promotes bone healing and enhances osteoblastic cell attachment, likely through increased collagen synthesis and extracellular matrix remodelling2,3,9,12,.

Both GHK and its copper(II) complex, GHK-Cu, exhibit potent antioxidant and anti-inflammatory properties3,9,12. The unbound peptide scavenges toxic lipid peroxidation products, such as 4-hydroxy-trans-2-nonenal and acrolein, which contribute to oxidative damage in conditions like diabetes and neurodegenerative disease3,9. When bound to copper, GHK-Cu further reduces inflammation by suppressing TNF-β and IL-6 production through inhibition of NF-κB p65 and p38 MAPK signalling, thereby limiting excessive inflammatory responses3,12.

At the molecular level, GHK-Cu modulates gene expression related to immune regulation and tissue repair, including YWHAB, MAP3K5, LMNA, APP, GNAQ, F3, NFATC2, and TGM23,13. In animal studies, treatment with GHK-Cu significantly reduced pro-inflammatory cytokines, such as TNF-β, IL-6, and IL-1β in injured tissue while increasing superoxide dismutase (SOD) activity and lowering reactive oxygen species (ROS) levels12. Histologic analysis revealed less oedema, reduced leukocyte infiltration, and overall preservation of tissue structure. Mechanistically, these protective effects were associated with inhibition of NF-κB and p38 MAPK pathways and activation of Nrf2-driven antioxidant defences, underscoring GHK-Cu’s dual role in inflammation control and oxidative protection3,12.

FDA considerations

At this time, GHK-Cu does not have FDA clearance for injection despite the fact that many anti-ageing and regenerative clinics are offering this peptide to their patients. Copper peptide is readily used as a cosmeceutical in medical-grade skincare.

Conclusions

Collectively, the research on GHK-Cu demonstrates its broad therapeutic and regenerative potential.

It exhibits potent anti-inflammatory and antioxidant properties9,12,14. These mechanisms highlight its capacity to modulate both inflammatory and oxidative stress pathways, suggesting clinical relevance in many inflammatory and aesthetic conditions3,12,14.

In summary, GHK-Cu emerges as a multifunctional bioactive molecule—one with regenerative, antioxidant, anti-inflammatory, and gene-modulatory properties. Its safety profile, biological versatility, and influence on pathways central to repair and longevity position it as a compelling candidate for future therapeutic and preventive applications in regenerative and aesthetic conditions.

Continued investigation, including well-designed human trials, is warranted3,12,14.

  • Declaration of interest none

References

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