GHK-Cu
GHK-Cu is the copper peptide already in half the serums on a skincare shelf, the active ingredient people go looking for once they read the label on a copper-peptide cream. It signals skin cells to build more collagen and remodel damaged tissue, which is the basis for its long run in anti-aging skincare. Most people meet it topically, in a cream or serum aimed at fine lines and skin texture, though a growing number inject it for broader recovery and anti-aging effects. Topical use is typically daily; injectable protocols run several days a week.
What it does
Skin texture and firmness
Fine lines and thinning skin are usually why people first go looking for a copper-peptide cream, and GHK-Cu is the ingredient actually doing the work in most of them. A 12-week trial in women with sun-damaged skin found a GHK-Cu cream and serum increased skin density and thickness and softened the depth of fine lines and wrinkles compared with a plain vehicle cream. It works by prompting skin cells to ramp up collagen production and general tissue remodeling. It remains regulated only as a cosmetic ingredient, never as an approved drug.
Sources: Leyden JJ, Grove, 2002, Pickart L, et al., 1980
Post-procedure comfort
Recovering from a CO2 laser resurfacing session is uncomfortable no matter what you put on it, and that is where GHK-Cu shows up in a lot of post-procedure regimens. In a controlled trial, people using a topical GHK-Cu regimen after resurfacing reported meaningfully higher satisfaction than those using a control regimen, applied the same way any other post-procedure skincare product would be, worked into whatever routine a dermatologist sets. Actual healing time in that same trial was not significantly different between the two groups; satisfaction was what moved, not speed.
Sources: Miller TR, Wagner, 2006
Systemic and injectable use
Some people want more than a cream can deliver and move to injecting GHK-Cu for broader anti-aging and recovery support, the same logic that drives injectable use of other topical-first peptides. The reasoning borrows from what the topical trials showed on skin and from animal wound-healing studies. Dosing communities describe titrating up over several weeks, several days a week. No human trial of injectable GHK-Cu exists, so this use rests entirely on extrapolation from a different route.
Dosing
Community reportedCommunity titration, 5x/week (peptidedosages.com)1.0 mg to 2.0 mg, 5 days/week
| Timeframe | Dosage | Frequency | Note |
|---|---|---|---|
| Weeks 1-4 | 1.0 mg | 5 days/week | Starting dose1 |
| Weeks 5-8 | 1.5 mg | 5 days/week | |
| Weeks 9-12+ | 2.0 mg | 5 days/week | Maintenance ceiling23 |
- Subcutaneous. An alternative protocol uses 2.0 mg per dose, three times weekly (about 6 mg/week total), weeks 1-12+.
- The site states plainly this is not a controlled human dose-ranging trial; dosing reflects practice conventions summarized by a compounding source, and the underlying research is mostly topical-formulation and animal wound-model data, not systemic subcutaneous human trials. Community members report both '5 mg M/W/F' and '2 mg daily' schedules with no consensus on which is better.
- No published human trial has established an injectable/systemic GHK-Cu dose for any indication. A commonly cited 2% cream concentration in the broader topical literature is a different, non-injectable route and is not comparable to this schedule.
Primary structure
GGlyHHisKLys
Full research
Evidence tier
GHK-Cu, injectable: Animal and in-vitro onlyGHK-Cu, topical: Human trials, not approved for this use
GHK-Cu, injectable: No human injectable trial of GHK-Cu was identified in any available source; injectable use rests entirely on animal wound-healing models and unsourced community-reported protocols. The topical evidence base should not be allowed to lend unearned credibility to the unstudied injectable route.
GHK-Cu, topical: Small controlled human RCTs exist for skin outcomes, a 12-week vehicle-controlled trial in photodamaged skin and a CO2-laser-resurfacing trial, but GHK-Cu remains unapproved as a drug for any indication and is regulated only as a cosmetic ingredient.
Identity
| Full name | GHK-Cu (copper tripeptide-1) |
|---|---|
| Class | Copper(II) complex of the naturally occurring human tripeptide glycyl-L-histidyl-L-lysine; regulated as a cosmetic ingredient, INCI name Copper Tripeptide-1 |
| Molecular weight | 403.9 g/mol |
| Sequence | Gly-His-Lys (GHK tripeptide), complexed with copper(II); free tripeptide molecular weight approximately 340.4 g/mol, versus approximately 403.9 g/mol for the copper complex |
Mechanism of action
Plain language
GHK-Cu acts as a signal that tells skin and other tissue cells to ramp up repair and collagen-building activity, partly by delivering copper into cells in a chemically quiet, non-reactive form, and partly by switching a large number of genes involved in tissue remodeling on or off.
Technical
The tripeptide's glycine residue is the primary copper-binding site; copper(II) redox activity is chemically silenced when complexed with GHK, proposed as the basis for non-toxic, targeted copper delivery to cells. In fibroblast culture, GHK-Cu at picomolar-to-nanomolar concentrations has been reported to stimulate synthesis of collagen types I, III, and V, glycosaminoglycans, and decorin. A large-scale gene-expression analysis reported GHK-Cu modulates expression of roughly 4,000 human genes, about 31 percent of genes analyzed in that dataset, upregulating a subset including collagen and DNA-repair genes and downregulating others including some pro-inflammatory signaling genes. This gene-expression breadth is itself a caution flag: a peptide affecting nearly a third of the analyzed genome is not acting through a single, well-isolated pathway, and the functional consequence of many of these individual gene changes in vivo, especially systemically after injection, is proposed and extrapolated rather than directly demonstrated in controlled human studies.
Sources: Pickart L, et al., 1980, Maquart FX, Pickart, 1988, Pickart L, Margolina, 2018
What it’s used for
Human trials, not approved for this use
- A randomized, evaluator-blinded, vehicle-controlled 12-week trial in women with photodamaged facial skin (n=71) reported that a GHK-Cu-containing cream and serum increased skin density and thickness and reduced fine-line and wrinkle depth versus vehicle.
Sources: Leyden JJ, Grove, 2002
- A separate randomized, blinded-evaluator trial of topical GHK-Cu skincare regimens after CO2 laser facial resurfacing found no statistically significant difference in the rate of erythema resolution between GHK-Cu and control regimens, but significantly higher patient-reported satisfaction in the GHK-Cu group.
Sources: Miller TR, Wagner, 2006
Off-label / community use
- Injectable GHK-Cu is used off-label in longevity, aesthetic, and recovery communities for systemic anti-aging, skin-quality, and wound or injury recovery claims, extrapolating from the topical cosmetic evidence base and from animal injectable data. This is anecdotal, community-driven use without controlled human injectable data.
Pharmacokinetics
| Injectable or systemic human pharmacokinetics |
Not established No citable figure. No human pharmacokinetic data, half-life, time to peak, or systemic bioavailability after subcutaneous injection, were identified for GHK-Cu in available sources; skin-penetration, systemic-absorption, tissue-distribution, and clearance data are explicitly noted as absent in the literature reviewed. |
|---|---|
| In-vitro fibroblast activity concentration |
Animal / in-vitro Biological activity reported at picomolar-to-nanomolar concentrations in fibroblast culture; this does not establish an in-vivo human pharmacokinetic profile. Sources: Pickart L, Margolina, 2018 |
Reconstitution
| Vial strength | Most commonly 50 mg lyophilized powder per vial (injectable/research form) |
|---|---|
| Diluent | Bacteriostatic water |
| Diluent volume | 2 mL (common vendor convention); alternatively 3 mL |
| Concentration | 25 mg/mL (2 mL diluent); approximately 16.7 mg/mL (3 mL diluent) |
Sources: Multiple commercial vendor
Dose calculator
Enter a vial strength, diluent volume, and desired dose to see the resulting concentration, dose volume, and units on a standard U-100 insulin syringe. Nothing entered here is saved, stored, or sent anywhere – the calculation runs only in your browser.
This calculator needs JavaScript. The arithmetic it runs is: concentration = vial strength in mg divided by diluent volume in mL; dose volume in mL = dose in mg divided by concentration; units on a U-100 syringe = dose volume in mL times 100.
Storage and post-reconstitution stability
Unopened storage
Vendor sources describe reconstituted GHK-Cu solutions as light-sensitive, since copper complexes are generally photoreactive, and recommend refrigerated storage; no published stability study specific to lyophilized, unreconstituted GHK-Cu was identified.
Post-reconstitution stability – Vendor claim
Described only as similar to other reconstituted peptides, weeks not months; no specific day figure given. Light-sensitive, refrigerated
No citable figure. No published stability study specific to GHK-Cu injectable solution was identified; this qualitative range is vendor guidance, not a validated figure.
Safety
Contraindications
- GHK-Cu, and copper supplementation generally, is contraindicated in individuals with Wilson disease and related genetic copper-metabolism disorders, and should be used with caution and medical supervision in anyone with hepatic disease or on copper-chelation therapy.
Sources: Agency for Toxic, 2024
Notable risks
- No controlled human safety data exist for injectable or systemic GHK-Cu. Topical human trials reported the cosmetic formulations as generally well tolerated, with no major adverse events highlighted in available summaries, though full adverse-event tables from the primary sources were not independently reviewed.
- GHK-Cu stimulates angiogenesis and modulates matrix metalloproteinase expression, pathways that overlap with those exploited by tumors, and free ionic copper has independently been reported elevated in the serum of several malignancy types and implicated in tumor angiogenesis via HIF-1alpha and VEGF signaling. Whether the chelated, redox-silenced form in GHK-Cu carries the same risk as free ionic copper is unresolved. Countervailing animal and in-vitro evidence exists showing GHK-Cu or related copper-peptide treatment inhibiting tumor growth in some models; the literature is mixed and context-dependent rather than settled in either direction.
Sources: Copper activates HIF-1alpha/GPER/VEGF, Skin Regenerative and, 2018
- The U.S. tolerable upper intake level for dietary copper in adults is 10,000 mcg per day, based on liver-damage risk, but this applies to oral or dietary intake, not to injected chelated-copper-peptide dosing, and no source establishes a safe systemic copper-loading threshold specific to injected GHK-Cu. Common signs of copper excess reported in the general toxicology literature include nausea, vomiting, diarrhea, and abdominal pain.
Sources: National Academies /, Agency for Toxic, 2024
Sources
- Pickart L, et al. Growth-modulating plasma tripeptide may function by facilitating copper uptake into cells. Nature (1980)
- Maquart FX, Pickart L, et al. Stimulation of collagen synthesis in fibroblast cultures by the tripeptide-copper complex. FEBS Lett (1988)
- Pickart L, Margolina A. Regenerative and Protective Actions of the GHK-Cu Peptide in the Light of the New Gene Data. Int J Mol Sci (2018)
- Leyden JJ, Grove GL, Barkovic S, Appa Y. Clinical Evaluation of a Copper Tripeptide Cream and Serum for Photodamaged Skin. J Cosmet Dermatol (2002)
- Miller TR, Wagner JD, Baack BR, Eisbach KJ. Effects of Topical Copper Tripeptide Complex on CO2 Laser-Resurfaced Skin. Arch Facial Plast Surg (2006)
- Agency for Toxic Substances and Disease Registry (ATSDR). Toxicological Profile for Copper (a peer-reviewed systematic literature compilation, not FDA/EMA prescribing information or a Federal Register notice) (2024)
- National Academies / NCBI Bookshelf. Copper. Dietary Reference Intakes
- Copper activates HIF-1alpha/GPER/VEGF signalling in cancer cells
- Skin Regenerative and Anti-Cancer Actions of Copper Peptides. MDPI (Cosmetics) (2018)
- Multiple commercial vendor and dosing-guide pages (e.g. perfectb.com, thepeptidecatalog.com, dosagepeptide.com), cited only to describe commercially sold vial strengths and vendor-stated reconstitution and dosing convention, not as evidence for any efficacy or safety claim
- thepeptidecatalog.com. GHK-Cu Topical vs Injectable: 10x Absorption Gap. Commercial source, cited only to document the acknowledged absence of injectable human trial data
- peptidedosages.com, GHK-Cu 50 mg vial dosage protocol
This is a research and educational reference, not medical advice. Nothing on this site is a recommendation to use any compound.