GHK-Cu
Also known as Copper peptide, Glycyl-L-histidyl-L-lysine copper, GHK copper complex, Copper tripeptide-1
GHK-Cu is a naturally occurring tripeptide bound to copper that declines with age. It is used topically for skin firmness, wrinkles and hair growth, and by injection for wound healing, skin remodeling and general tissue repair.
Reviewed by the amino101 editorial team. , first published .
Quick start
What people commonly do. Not a prescription.- Typical dose
- 1 to 2 mg (injectable); 0.5 to 3 percent (topical)
- How often
- once daily (injectable); once or twice daily (topical)
- Where
- Subcutaneous, belly, thigh or near a scar or wound for local effect; topical on clean skin or scalp
- Timing
- many people inject in the evening; topical after cleansing and before heavier creams
- Effects timeline
- wound and scar changes 2 to 4 weeks, skin texture and firmness 6 to 12 weeks, hair 3 to 6 months
- Storage
- fridge 2 to 8 C once mixed, use within 4 weeks; the solution should stay clear and blue
- Cycle length
- 4 to 8 weeks injectable; topical use is ongoing
- Break between
- 2 to 4 weeks off injectable, then reassess; no break needed for topical
Overview
GHK is a three amino acid peptide (glycine, histidine, lysine) that occurs naturally in human plasma, saliva and urine. It binds copper ions tightly, and the copper complex is what most people mean by GHK-Cu. It was isolated in 1973 by Loren Pickart, who noticed that plasma from young people made old liver cells behave more youthfully and traced the effect to this small peptide. Plasma levels fall sharply between age 20 and 60, which is part of why it attracted interest as an anti-aging compound.
The topical evidence is the strongest part of the story. Several controlled human studies of GHK-Cu creams showed improvements in skin thickness, elasticity, fine lines and photodamage, comparable to or better than vitamin C and retinol in some comparisons. Human and animal wound healing studies show faster closure and better collagen organization. For hair, small human trials and rodent studies suggest increased follicle size and reduced shedding.
Injectable use is a newer trend with much less data. Gene expression studies show that GHK modulates thousands of genes toward a more regenerative, less inflammatory profile, which is the basis for claims about systemic effects. Animal work suggests benefit in lung injury and nerve regeneration. There are no human trials of subcutaneous GHK-Cu, so systemic dosing protocols are entirely community derived.
How it works
GHK-Cu acts as a signaling molecule that shifts gene expression toward tissue repair. It stimulates fibroblasts to produce collagen, elastin and glycosaminoglycans while also increasing the enzymes that break down damaged collagen, which lets tissue remodel rather than simply thicken. It attracts immune and repair cells to wounds, promotes new blood vessel growth and has antioxidant and anti-inflammatory effects, partly through copper delivery to enzymes like superoxide dismutase. Large scale gene expression screens found that GHK influences over 4000 genes, including suppression of genes tied to fibrosis, inflammation and cancer metastasis, and activation of those tied to DNA repair. Copper itself is essential for lysyl oxidase, the enzyme that cross-links collagen.
Where the research stands
Skin aging and photodamageStrong evidence
- Fine lines, elasticity and skin thickness. Several controlled human trials of topical GHK-Cu cream showed measurable improvement over 12 weeks.
- Collagen production. A human comparison found GHK-Cu outperformed vitamin C and retinoic acid for collagen stimulation in treated skin.
Wound and scar healingModerate evidence
- Skin wound closure. Rat and rabbit wound models show faster closure and better organized collagen; small human wound studies point the same way.
- Post-surgical and scar remodeling. Mechanistic and animal evidence for balanced collagen turnover; human data for injectable use around scars is anecdotal.
Hair growthEmerging
- Follicle size and shedding. Mouse studies and a few small human trials report larger follicles and less shedding; far weaker evidence than minoxidil or finasteride.
Systemic repair and anti-inflammatory effectsWeak or mixed
- Lung injury and nerve regeneration. Animal and gene expression studies only; no human trial of injectable GHK-Cu exists for any systemic purpose.
- human RCTTopical GHK-Cu cream improved skin thickness, elasticity and reduced wrinkles in women with photoaged skin over 12 weeks.
- human pilotGHK-Cu outperformed vitamin C and retinoic acid for collagen production in a comparison of topical treatments.
- in vitroGene profiling showed GHK reverses expression patterns associated with COPD, cancer metastasis and inflammation.
- rodentAccelerated wound closure and improved collagen deposition in rat and rabbit skin wound models.
- human pilotIncreased hair follicle size and improved hair growth in mouse models and small human trials.
Rodent and in vitro mean no human data for that finding. Human pilot means small, often uncontrolled. Human RCT means randomized and controlled. Clinical means an approved drug with regulatory data.
Levels over time
Modeled from the half-life. Illustrative, not measured.A half-life of 45 min against dosing every 24 h means each dose has cleared before the next. Nothing stacks; you start from zero every time, and the tissue effect is what carries over.
The peptide is gone from blood quickly, but its job is to switch on repair genes in fibroblasts and other cells, so daily injections or twice daily topical use are aimed at steady tissue exposure rather than sustained blood levels.
GHK-Cu dosage and protocols
Injectable protocols typically run 4 to 8 weeks then pause, mainly because there is no long term human safety data and because copper load is a theoretical concern. Topical use is continuous; benefits fade if you stop, as with any skin treatment.
| Goal | Dose | Frequency | Route |
|---|---|---|---|
| Skin remodeling, systemic | 1 to 2 mg | once daily | Subcutaneous, abdomen or thigh |
| Scar or wound, local | 1 mg | once daily | Subcutaneous near the scar, rotating sites |
| Skin aging, topical | 0.5 to 3 percent cream or serum | once or twice daily | Topical on face and neck |
| Hair, topical | 1 to 2 percent solution | once daily | Topical on scalp, often with weekly microneedling |
Food makes no difference. Evening injections are common because the stinging is easier to sleep through, and diluting to a lower concentration and injecting slowly reduces the reaction. Topically, apply it away from vitamin C serums, which reduce the copper, and let it absorb before layering anything else.
Injectable protocols commonly report 1 to 2 mg daily, sometimes split. Topical products use 0.5 to 3 percent. Higher injectable doses cause more stinging and bruising.
Dose calculator
U-100 insulin syringeUnits are a volume on the syringe, not an amount of peptide. Concentration changes every time you change the water volume. The standalone calculator explains the math.
| Vial | Suggested water | Concentration | Low dose draw |
|---|---|---|---|
| 50 mg | 3 mL | 16.667 mg/mL | 6 units |
| 100 mg | 6 mL | 16.667 mg/mL | 6 units |
How to reconstitute GHK-Cu
- 1
Wash your hands and wipe the work surface. Swab both vial stoppers with alcohol and let them dry.
- 2
Pick the water volume with the calculator above and write it on the vial. The concentration means nothing without it.
- 3
Draw the bacteriostatic water into a mixing syringe.
- 4
Insert at an angle and let the water run down the inside wall. Never squirt it straight onto the powder.
- 5
Swirl gently or leave it to dissolve. Do not shake.
- 6
Label with the date and water volume. Store in the fridge at 2 to 8 C and use within about 4 weeks.
- 7
Unmixed vials keep for months in the fridge and longer in the freezer, sealed and out of light.
- Full walkthrough with syringe reading and site rotation: reconstitution guide.
- ✓White, fluffy cake
Lyophilized powder should look like a small white puck or fluffy cake at the bottom of the vial. That is a proper freeze-dry.
- ✓Clear after mixing
Once dissolved the solution should be water-clear with nothing floating in it.
- !Slight clumping
Small clumps that dissolve with gentle swirling are fine. Shipping compacts powder.
- ✕Collapsed or melted
Powder stuck to the sides, glassy, or shrunken means it got hot in transit. Contact the vendor.
- ✕Cloudy or particles
Persistent cloudiness or visible particles after mixing means degraded or contaminated product. Do not use it.
- Week 1 to 2
Injection stinging, redness and some bruising are expected; topical users may see slightly calmer, more hydrated skin but nothing structural yet.
- Week 3 to 6
Scars and wounds look flatter and less red; skin texture starts to feel smoother, which is the earliest the human topical trials measured change.
- Week 8 to 12
Firmness, elasticity and fine line improvement become visible in line with the 12 week trial data; hair changes need 3 to 6 months to judge.
Interactions and stacking
BPC-157compatible
Common post-injury and post-surgical stack; BPC-157 handles tendon and soft tissue while GHK-Cu handles collagen and skin, but keep them in separate syringes.
TB-500compatible
Both encourage cell migration and vessel growth and are used together in healing protocols; inject separately.
AHK-Cusynergistic
The two copper tripeptides are combined in scalp serums, AHK-Cu for the follicle and GHK-Cu for the surrounding skin.
SNAP-8compatible
SNAP-8 targets expression lines while GHK-Cu targets skin structure, so topical routines often include both.
Vitamin C serumscaution
Ascorbic acid reduces the copper complex and can inactivate it; use them at different times of day.
Retinoidscompatible
Retinol and GHK-Cu work through different pathways and are often alternated, though using both on sensitive skin can add up to irritation.
Copper supplements or Wilson disease treatmentavoid
Anyone with a copper metabolism disorder, or taking high dose copper, should not add injectable copper peptide on top.
Adds tendon and soft tissue repair to the collagen and skin remodeling of GHK-Cu for post-injury or post-surgical recovery.
Both promote cell migration and vessel growth, used together in comprehensive healing protocols.
AHK-Cu is used topically for hair alongside GHK-Cu for a broader scalp protocol.
Safety
- ▲Injection site stinging, redness and bruising, very common above 2 mg per mL
- ▲Skin irritation or a rash from topical products, more likely with high copper content
- ▲Temporary nausea or metallic taste after injection
- ▲Headache or fatigue in some users
- ▲Discoloration of the solution or skin if the product has degraded
- ▲Injection site stinging, redness and bruising are very common, especially at concentrations above 2 mg per mL.
- ▲Injectable use has no human safety data. Copper accumulation is a theoretical concern with high or long term dosing.
- ▲People with Wilson disease or other copper metabolism disorders should avoid it.
- ▲Topical products with high copper content can cause irritation; patch test first.
- ▲It is a blue solution. If your vial is colorless it is likely plain GHK without copper, or degraded.
- ■Injection sites become hard, hot or increasingly painful rather than settling within a day or two
- ■A persistent rash, hives or swelling develops
- ■You have or suspect a copper metabolism disorder such as Wilson disease
- ■Unusual fatigue, abdominal pain or jaundice, which could point to copper overload
- ■The reconstituted solution has turned cloudy or lost its blue color
Community poll
Self-reported by visitors. Not clinical evidence.GHK-Cu: frequently asked
Topical or injectable, which is better?
For skin appearance, topical has actual human trial support and is the sensible starting point. Injectable is used by people who want systemic effects or faster results on scars and wounds, but it is unstudied in humans. Many people use both.
Why does it sting so much when injected?
The copper complex is irritating to tissue at the concentrations people typically use. Diluting to a lower concentration, injecting slowly and rotating sites reduces the reaction. Some people mix it with a small amount of lidocaine, though that is not recommended without medical guidance.
Can GHK-Cu help with hair loss?
There is reasonable animal evidence and a few small human studies showing thicker hair and larger follicles. It is not as well proven as minoxidil or finasteride, and most people use it as an add-on rather than a replacement. Topical scalp application and microneedling are the common approaches.
Can I mix GHK-Cu with other peptides in the same syringe?
Copper can interact with other peptides and some people report that mixing changes the solution color. It is safer to inject it separately. Do not combine it with vitamin C serums topically, since ascorbic acid can reduce the copper.
References
- GHK peptide as a natural modulator of multiple cellular pathways in skin regeneration (review). BioMed Research International, 2015
- The human tri-peptide GHK and tissue remodeling. Journal of Biomaterials Science, Polymer Edition, 2008
- GHK-Cu may prevent oxidative stress in skin by regulating copper and modifying expression of numerous antioxidant genes. Cosmetics, 2015
- Effects of copper tripeptide on the growth and expression of growth factors by normal and irradiated fibroblasts. Archives of Facial Plastic Surgery, 2007