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.
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.
What the research shows
- 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.
Evidence labels: 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.
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.
Dosing and protocol
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.
4-8 weeks, then reassess. Topical use is ongoing.
Many people inject in the evening. Injection site pain is common, so rotating sites helps. Some inject near scars or wounds for local effect.
| 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 |
Lyophilized: fridge, away from light. The blue color should be uniform. Reconstituted: fridge 2-8C, use within 4 weeks. Discard if the solution turns cloudy or loses color.
Cautions
- ▲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.
Commonly stacked with
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.
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