# GHK-Cu - Canonical: https://residue.info/c/ghk-cu/ - Also called: Copper tripeptide-1, Prezatide copper, Glycyl-L-histidyl-L-lysine copper - Evidence grade: C (Limited / early human data). One small randomized human study (13 completers, topical) found no objective difference; most claims come from laboratory and animal work and from reviews. - Status: Not FDA-approved · injectable-route nomination withdrawn - PubChem CID: 71587328 - Updated: 2026-10-19 · Reviewed by: Residue Editorial Team GHK-Cu is the tripeptide glycyl-L-histidyl-L-lysine bound to a copper(II) ion. GHK occurs in human plasma and declines with age; laboratory work links GHK-Cu to collagen synthesis and wound repair [1]. The only randomized human study found, after laser resurfacing, showed no objective difference versus a regimen without it [2]. FDA lists GHK-Cu for injectable routes among withdrawn compounding nominations [3]. ## Key findings - GHK is present in human plasma, saliva and urine but declines with age; it is proposed to act as a complex with copper(II) [1]. (anchor: https://residue.info/c/ghk-cu/#kf-pmid-26236730) - Reviews describe stimulation of collagen, elastin and glycosaminoglycan synthesis and of fibroblast and keratinocyte proliferation in experimental systems [4][5]. (anchor: https://residue.info/c/ghk-cu/#kf-pmid-18644225) - In a randomized study after CO₂ laser resurfacing (13 completers), blinded evaluation found no difference in erythema resolution or wrinkles; only a patient questionnaire favored GHK-Cu (p=0.04) [2]. (anchor: https://residue.info/c/ghk-cu/#kf-pmid-16847171) - GHK was discovered in 1973 as an activity in human albumin [6]. (anchor: https://residue.info/c/ghk-cu/#kf-pmid-22666519) - FDA cites immunogenicity risk for injectable GHK-Cu and says there are limited human data to inform safety [3]. (anchor: https://residue.info/c/ghk-cu/#kf-fda-cat2) ## Effects by system - Skin (topical) (grade C): No objective difference after laser resurfacing in a 13-patient RCT; subjective skin-quality rating favored GHK-Cu [2]. (anchor: https://residue.info/c/ghk-cu/#effect-skin-topical) - Wound healing (grade D): Accelerated wound healing in rats, mice, pigs and dogs, per review [1]. (anchor: https://residue.info/c/ghk-cu/#effect-wound-healing) - Gene expression (grade D): Reported to up- and down-regulate at least 4,000 human genes in expression datasets [1][5]. (anchor: https://residue.info/c/ghk-cu/#effect-gene-expression) - Injectable use (grade D): Limited human safety data; FDA cites immunogenicity risk [3]. (anchor: https://residue.info/c/ghk-cu/#effect-injectable-use) ## What is GHK-Cu? GHK is the tripeptide Gly-His-Lys. It binds copper(II) with an affinity similar to the copper-transport site on albumin, forming the complex GHK-Cu [4]. It was discovered in 1973 as an activity in human albumin that caused old human liver tissue to synthesize proteins like younger tissue [6]. GHK is present in human plasma, saliva and urine and its level declines with age [1]. PubChem's record for the copper complex (prezatide copper) is used for the identifiers above [7]. ## How is GHK-Cu thought to work? Reviews describe GHK-Cu as a modulator of tissue remodeling. In experimental systems it attracts repair cells such as macrophages and capillary cells, has anti-inflammatory and antioxidant actions, increases synthesis of collagen, elastin, metalloproteinases and growth factors, and increases proliferation of fibroblasts and keratinocytes [4]. More recent work used gene-expression data to propose that GHK regulates many biochemical pathways at once [5]. These reviews are enthusiastic in tone — one describes GHK's actions as all appearing "health positive" [5]. They summarize mechanism well but are not evidence of clinical effect. ## Is there evidence in humans? **The randomized study.** Patients undergoing CO₂ laser resurfacing around the mouth were randomized to post-treatment skin regimens with or without GHK-Cu. Thirteen completed the study. Computer analysis and blinded evaluators found no significant differences in erythema resolution, and all patients improved in wrinkles and skin quality with no between-group difference. A validated patient questionnaire showed a significant difference favoring GHK-Cu for overall skin quality (p=0.04) [2]. **Cosmetic claims.** Reviews state that in cosmetic products GHK-Cu has been found to tighten skin, improve elasticity and reduce fine lines [1]; the underlying cosmetic studies are mostly not indexed as clinical trials in PubMed [8]. **Registered studies.** ClinicalTrials.gov lists a recruiting phase 2 trial of topical GHK-Cu gel for acute skin wounds [9] and a completed facial-skin study [10]. FDA's withdrawn-nominations list includes "GHK-Cu (for injectable routes of administration)". It notes that compounded injectable GHK-Cu may pose risk for immunogenicity due to aggregation and peptide-related impurities, and that there are limited data in humans to inform safety [3]. The listing is route-specific; it does not address topical cosmetic use. ## What is still unknown? - **Adequately powered randomized trials** with objective skin or wound endpoints. - **Any controlled human data for injection**, the route FDA flags [3]. ## Frequently asked questions **What is GHK-Cu?** A complex of the tripeptide glycyl-L-histidyl-L-lysine (GHK) with a copper(II) ion. GHK has a copper affinity similar to the copper-transport site on albumin [4]. **Does GHK-Cu work for skin?** Laboratory and animal data are extensive [1]. In the one randomized human study we found, 13 patients after laser resurfacing showed no objective differences in redness or wrinkles; a questionnaire favored GHK-Cu [2]. **Is injectable GHK-Cu FDA-approved?** No. FDA lists 'GHK-Cu (for injectable routes of administration)' among withdrawn compounding nominations, citing immunogenicity risk and limited human safety data [3]. **Are there clinical trials of GHK-Cu?** ClinicalTrials.gov lists a small number, including a recruiting phase 2 trial of topical gel for acute skin wounds [9]. ## Sources [1] GHK Peptide as a Natural Modulator of Multiple Cellular Pathways in Skin Regeneration. Pickart L et al. Biomed Res Int. 2015. https://pubmed.ncbi.nlm.nih.gov/26236730/ [2] Effects of topical copper tripeptide complex on CO2 laser-resurfaced skin. Miller TR et al. Arch Facial Plast Surg. 2006. https://pubmed.ncbi.nlm.nih.gov/16847171/ [3] Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks. U.S. FDA, content current as of 04/22/2026. https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks [4] The human tri-peptide GHK and tissue remodeling. Pickart L J Biomater Sci Polym Ed. 2008. https://pubmed.ncbi.nlm.nih.gov/18644225/ [5] Regenerative and Protective Actions of the GHK-Cu Peptide in the Light of the New Gene Data. Pickart L & Margolina A Int J Mol Sci. 2018. https://pubmed.ncbi.nlm.nih.gov/29986520/ [6] The human tripeptide GHK-Cu in prevention of oxidative stress and degenerative conditions of aging: implications for cognitive health. Pickart L et al. Oxid Med Cell Longev. 2012. https://pubmed.ncbi.nlm.nih.gov/22666519/ [7] PubChem compound record: Prezatide copper. C14H23CuN6O4+ · MW 402.92 g/mol. https://pubchem.ncbi.nlm.nih.gov/compound/71587328 [8] PubMed search: (GHK-Cu[tiab] OR "copper tripeptide"[tiab] OR "glycyl-histidyl-lysine"[tiab] OR "prezatide"[tiab]). 134 records at fetch. https://pubmed.ncbi.nlm.nih.gov/?term=(GHK-Cu%5Btiab%5D%20OR%20%22copper%20tripeptide%22%5Btiab%5D%20OR%20%22glycyl-histidyl-lysine%22%5Btiab%5D%20OR%20%22prezatide%22%5Btiab%5D) [9] Topical GHK-Cu Gel for Acute Skin Wound Healing. Hudson Biotech · PHASE2 · recruiting. https://clinicaltrials.gov/study/NCT07437586 [10] Trial Assessing the Impact on Facial Skin Quality, Hydration, and Skin Barrier of Three (3) Hydrafacial Treatments in Adults of All Skin Types.. Austin Institute for Clinical Research · PHASE4 · completed. https://clinicaltrials.gov/study/NCT05932732 --- From Residue. Research and education only; not medical advice. Quote with attribution and a link to the canonical page.