GHK-Cu
Glycyl-L-histidyl-L-lysine copper(II) complex · Copper tripeptide-1 · Copper peptide · Cu-GHK · Prezatide copper acetate
Copper-carrying tripeptide studied for collagen synthesis, wound repair and skin remodelling.
Typical dose
2 mg
1x daily
Range
1–3
mg
Half-life
—
see Dosing
Evidence
Early human
Topical · Subcutaneous
What it is
GHK is a naturally occurring human tripeptide that binds copper(II) with high affinity. Plasma levels are around 200 ng/mL in your twenties and fall to roughly 80 ng/mL — about 40% of the peak — by age sixty, which is the origin of most of the anti-ageing framing around it. The copper-bound form, GHK-Cu, is the biologically active species and is what gets sold.
Most of the evidence base is topical and cosmetic: controlled studies of copper-peptide creams on facial skin, hair follicles and wound beds, showing increased collagen and glycosaminoglycan synthesis and improved wound closure. Those trials are generally small and often industry-run, but they are real human data on real endpoints.
Injectable GHK-Cu is a different proposition. There is no human trial data for subcutaneous use at all, and unlike a peptide such as BPC-157 the compound carries an actual heavy metal into you. Copper is essential in microgram quantities and toxic in excess, and injecting it bypasses the gut's tight absorption control. This is the one peptide in the repair category where dose ceilings and cycle length are a genuine toxicology issue rather than a precaution.
How it works
GHK-Cu acts largely as a copper delivery vehicle and a gene-expression modulator. It shuttles copper to enzymes that need it — lysyl oxidase, which cross-links collagen and elastin, and superoxide dismutase, which handles oxidative stress — and it modulates the balance between matrix metalloproteinases and their tissue inhibitors, so it drives both the breakdown of damaged matrix and the deposition of new collagen, decorin and glycosaminoglycans.
Gene-expression profiling has shown GHK shifting expression of a very large number of genes, broadly in the direction of tissue remodelling and away from inflammatory and fibrotic programmes. That breadth is why the literature makes claims across skin, hair, wound and nerve tissue, and also why the mechanism is better described as pleiotropic than as targeted.
Dosing
GHK-Cu is about 16% copper by mass, so 2 mg delivers roughly 315 mcg of elemental copper straight past the gut's absorption control — this is why cycles are kept short rather than run continuously.
Reconstitution calculator
Pre-loaded with GHK-Cu’s vial size, water volume and typical dose. Change anything.
Typical: 2 mg · range 1–3
Draw to
20 u
0.2 mL · 2 mg
Concentration
10 mg/mL
100 mcg per unit
Doses per vial
25
Vial lasts
3 weeks 4 days
Draw to 20 units on the barrel.
Once mixed
Refrigerate at 2-8 C in the dark and use within about 30 days; discard immediately if the blue colour fades or the solution goes cloudy.
Add the bacteriostatic water down the vial wall and swirl gently; the solution should go a clear deep blue, and cloudiness or a green-brown tint means the copper complex has degraded and the vial should be discarded. 50 mg in 5 mL gives 10 mg/mL, so a 2 mg dose is 0.2 mL, or 20 units on a U-100 insulin syringe.
Storage
Before mixing
Sealed, dry and dark at 2-8 C for two years or more; light exposure degrades the copper complex faster than it does most peptides.
After mixing
Refrigerate at 2-8 C in the dark and use within about 30 days; discard immediately if the blue colour fades or the solution goes cloudy.
Reported benefits
- ▪Stimulates collagen, elastin and glycosaminoglycan synthesis in human skin studies
- ▪Improves wound closure and reduces scar formation in controlled topical trials
- ▪Modulates matrix metalloproteinases, clearing damaged matrix as well as laying down new
- ▪Antioxidant activity via copper delivery to superoxide dismutase
- ▪Topical use has a genuinely good safety record over decades of cosmetic sale
- ▪Reported improvements in hair follicle size and skin firmness with sustained topical use
Side effects
- ▪Marked injection-site stinging, redness and swelling — the most commonly reported problem by a wide margin
- ▪Blue-green staining or discoloration at the injection site
- ▪Nausea, metallic taste or headache, usually signs of dosing too high or too long
- ▪Copper accumulation with extended use, which can suppress zinc status and cause fatigue and anaemia
- ▪Topical use can cause irritation or contact dermatitis on sensitive skin
Do not use if
- ▪Wilson's disease or any other disorder of copper handling — absolute contraindication
- ▪Existing copper overload, or ongoing high-dose copper supplementation
- ▪Significant liver or kidney impairment, since both handle copper clearance
- ▪Pregnancy and breastfeeding — no data
- ▪Active cancer, given the compound's angiogenic and pro-proliferative activity
Evidence level — Early human
Small or early-phase human studies only.
Sold legally worldwide as a topical cosmetic ingredient; the injectable form is not approved as a drug anywhere and is supplied only as a research chemical.
Commonly run with
BPC-157
Gastric-juice-derived pentadecapeptide studied for tendon, ligament and gut healing.
250 mcg · 1x daily (some split into 2x daily during an acute injury)
TB-500
Actin-regulating thymosin peptide used for soft-tissue repair and range of motion.
2.5 mg · 2x weekly during loading, then once every 1-2 weeks for maintenance
KPV
Tripeptide tail of alpha-MSH used to damp gut and skin inflammation.
500 mcg · 1x daily
GHK-Cu FAQ
Should I inject it or just use it topically?+
For skin, hair and superficial scarring, topical is where all the human evidence sits and it avoids the copper-loading problem entirely. Injection is used by people chasing systemic connective-tissue and wound effects, but it has zero human trial support and carries a real heavy-metal dose.
Why does everyone insist on short cycles?+
Because you are injecting copper, not just a peptide. Roughly 16% of the mass is elemental copper delivered subcutaneously, bypassing the intestinal regulation that normally keeps copper status in range. Two to four weeks on with an equal break off is the standard community ceiling, and running it continuously is how people end up with copper-zinc imbalance.
Should I take zinc alongside it?+
Copper and zinc compete, and sustained copper loading can drive zinc down. If you are running injectable GHK-Cu for more than a couple of weeks, keeping a normal dietary zinc intake is sensible — but megadosing zinc to counteract it just swaps one imbalance for the other.
The solution turned pale or cloudy. Is it still usable?+
No. A healthy reconstituted GHK-Cu vial is a clear, deep blue. Colour loss or cloudiness means the copper complex has broken down, and at that point you have no idea what you are injecting. Discard it.
References
- 1.GHK Peptide as a Natural Modulator of Multiple Cellular Pathways in Skin Regeneration — BioMed Research International (2015) PMID 26236730
- 2.The human tri-peptide GHK and tissue remodeling — Journal of Biomaterials Science, Polymer Edition (2008) PMID 18644225
- 3.The human tripeptide GHK-Cu in prevention of oxidative stress and degenerative conditions of aging: implications for cognitive health — Oxidative Medicine and Cellular Longevity (2012) PMID 22666519
More healing & recovery
BPC-157
Gastric-juice-derived pentadecapeptide studied for tendon, ligament and gut healing.
250 mcg · 1x daily (some split into 2x daily during an acute injury)
KPV
Tripeptide tail of alpha-MSH used to damp gut and skin inflammation.
500 mcg · 1x daily
TB-500
Actin-regulating thymosin peptide used for soft-tissue repair and range of motion.
2.5 mg · 2x weekly during loading, then once every 1-2 weeks for maintenance