# GHK-Cu Dosage Research Context — Concentrations, routes, and stability > Research-context summary of GHK-Cu doses, routes, and stability across cell culture, rodent studies, and topical formulations. Not dosing guidance for humans. What the published papers measured — not a regimen for any human application. ## What the research used — not what to take This page describes concentrations and routes that investigators have used in published studies — not a dosing guide for humans. In cell culture, the active range is roughly 1 to 100 nanomolar, with effects peaking around 10 nM. In rodent systemic studies, doses run from 0.5 micrograms per kilogram for acute behavioral effects up to 20 milligrams per kilogram for oral gavage in a mouse colitis model. Topical cosmetic formulations typically use 0.05 to 2 percent w/w of Copper Tripeptide-1. GHK-Cu is not approved as a drug by the FDA for any indication. The injectable regulatory status has been in flux since the April 2026 Category 2 removal. Everything here is research context, not a recommendation. ## How to read this page Everything below is research context, pulled directly from the published literature. It describes what concentrations and routes investigators have used in cells, in rodents, in scaffolds, and in topical cosmetic studies. It does not describe what should be administered to humans for any purpose. GHK-Cu is not approved by the FDA as a drug for any human indication. This site is an editorial digest of the research. It is not a clinic, a pharmacy, or a vendor. The clippings below are organized by study type — in vitro, rodent systemic, rodent oral, topical, transdermal, scaffold — because that is how the literature itself is organized. ## In vitro mechanistic concentrations Cell culture mechanistic studies have consistently used GHK-Cu in the 1 to 100 nanomolar range, with bell-shaped potency peaks around 10 nM [5][8][21]. The Connectivity Map and LINCS analyses that produced the 4,192-gene estimate were run at these concentrations [5]. Endothelial proliferation and Matrigel tube formation in HUVECs were observed at 10 nM [21]. Collagen IV upregulation in fibroblasts at 25.4-fold required the GHK-Cu / LMW hyaluronic acid 1:9 stoichiometry [8]. For neuroprotection studies against acute metal toxicity, concentrations are higher — Min and colleagues used 5 to 10 mM GHK against 125 to 500 microM Cu2+ or Zn2+ in BV2 microglia and primary CNS cells, because the protective effect was tested against an explicitly excitotoxic metal load [9]. These are stress-paradigm concentrations and should be read as such. ## Rodent systemic studies Intraperitoneal dosing in mice has run from 0.2 microg/g/day at the low end to 20 microg/g/day at the high end in chronic dosing studies. Zhang and colleagues administered GHK-Cu intraperitoneally at 0.2, 2, and 20 microg/g/day for 12 weeks in a cigarette-smoke-induced emphysema model in male C57BL/6J mice, with the two higher doses showing significant histological and biochemical effects [2]. Behavioral studies in rats have used much lower doses. Bobyntsev and colleagues observed acute anxiolytic-like and anti-aggression effects at 0.5 microg/kg intraperitoneal in Wistar rats, with measurable effects within 12 minutes of administration [13]. The behavioral effect is copper-independent — that is, the free peptide produced the effect. Oral dosing in rodents is less common but exists. Mao and colleagues used 20 mg/kg by oral gavage daily for 14 days in BALB/c mice with DSS-induced colitis, producing the SIRT1-binding mechanism described above [4]. Whether the oral route generalizes to other indications, and whether enteric proteolysis allows comparable bioavailability in larger animals, are open questions in the literature. ## Topical and transdermal research formulations Topical cosmetic formulations have used Copper Tripeptide-1 (the INCI name for GHK-Cu) in the 0.05 percent to 2 percent w/w range in creams, serums, gels, and wound dressings [18][19]. The 2024 McGill ultrasound study used a topical formulation applied twice daily for 12 weeks in 21 subjects, reporting a 28 percent mean increase in subdermal echogenic density and approximately 51 percent in the top quartile of responders [17]. Transdermal permeation studies have characterized the physical barrier as the rate limit. Mohammed and colleagues showed that polymeric microneedle pre-treatment increased GHK-Cu permeation through ex-vivo human skin to 134 +/- 12 nmol over 9 hours — orders of magnitude higher than the negligible passive flux through intact stratum corneum [22]. That finding reframes topical GHK-Cu: the rate-limiting barrier is physical, not biochemical. ## Scaffold and dressing delivery The scaffold literature is where the most novel delivery strategies live. Polydopamine-coated 3D-printed silk scaffolds have been used for controlled-release GHK-Cu in a rat calvarial defect model, pairing peptide signaling with structural osteoconductive support [6]. Composite hydrogels of egg-white, konjac glucomannan, and GHK-Cu have been used for full-thickness infected wounds [7]. GHK-loaded collagen films were used in the diabetic rat wound model [15]. GHK-AgNP conjugates have been used at MICs of 8 microg/mL against E. coli and S. aureus [20]. These are research vehicles, designed to characterize what GHK-Cu does in a controlled tissue-engineering setting. They are not products. ## Stability and storage in the laboratory The 1:1 Cu:peptide complex in slightly acidic solution is the most stable and biologically active form [16]. In solution the complex is photo- and oxidation-sensitive; dry lyophilized powder is robust under refrigeration. Reconstitution and storage practices in the research literature vary by lab but tend toward bacteriostatic water for short-term studies and lyophilized stocks held at minus 20 degrees Celsius for longer-term use. Glutathione reduces Cu(II)-GHK via a characterized Cu(II)-thiolate intermediate without releasing free copper [16]. That detail is mechanistically important for understanding why GHK-Cu is well-tolerated in physiological conditions, and is one reason researchers handle it differently from uncomplexed copper salts. ## Half-life and pharmacokinetic notes Free GHK has a short plasma half-life on the order of minutes due to plasma peptidases. The copper-bound complex is markedly more stable in vivo [16]. Tissue retention after topical or microneedle delivery extends to hours-to-days depending on vehicle and study design [22]. Endogenous plasma concentrations decline from approximately 200 ng/mL in the third decade of life to roughly 80 ng/mL by the seventh decade [5][14]. That age-related drop is the demographic framing for the supplementation hypothesis, but it is not a pharmacokinetic measurement of any exogenous product. Detailed human pharmacokinetics across the various systemic routes the rodent literature has explored are not well characterized. That is a real gap in the file. ## What this page deliberately does not say This page does not recommend a human dose. It does not describe a regimen. It does not endorse compounded injectable GHK-Cu, which lost its FDA Category 2 compounding status in April 2026 and is currently in an uncertain regulatory state. It does not endorse any vendor, any pharmacy, any cosmetic brand, or any research-chemical supplier. What it does is describe what the research community has actually used to study the molecule — because that is the question the literature actually answers, and because anything else would be inventing a recommendation the published evidence does not support. --- A curated scrapbook of peer-reviewed GHK-Cu literature — not a clinic, not a vendor, not medical advice.