GHK-Cu is glycyl-histidyl-lysine, a tripeptide that occurs naturally in the human body, bound to a copper ion [1]. It turns up in skin serums, hair products and, lately, vials marketed for injection.
The list of benefits attached to it is long. The useful question is which of them were measured in people, and which come from a dish of cells or a lab animal. This page sorts them that way.
Where the list of benefits comes from
A 2008 review set out its proposed actions [1]. They include drawing repair cells to a wound, calming inflammation, and raising the production of collagen, elastin and growth factors.
The same review lists increases in fibroblast and keratinocyte growth, blood-vessel growth, nerve outgrowth and hair follicle size. It also cites liver protection and stomach and bone healing, largely from animal models.
Those are laboratory mechanisms, and most were measured in cultured cells or animals. A mechanism explains how something might work in a person; it does not show that it does, which is why the human trials below matter more than the length of the list.
Skin: the most-studied use
Skin is where copper peptide has been tested most in people, as a product applied to the skin rather than injected.
A 2026 systematic review searched three databases through March 2026 for GHK-Cu used on its own for aesthetic purposes [2]. It found 20 studies, of which 18 were preclinical and 2 were randomized trials.
In those human studies, GHK-Cu improved patient-reported satisfaction after laser resurfacing and reduced wrinkle volume and depth against controls. The reviewers still called the clinical evidence limited, with few well-designed trials and no standard formulation or dose.
The 2008 review describes controlled studies on aged skin that found tighter, firmer skin with fewer fine lines [1]. How topical and injected forms compare is covered in GHK-Cu topical vs injected.
Wound healing: two trials, two answers
The two oldest human trials in this set were in chronic wounds, and they did not agree.
In 1994, a multicenter randomized, evaluator-blinded trial tested a GHK-Cu gel on diabetic foot ulcers, on top of standard wound care [3]. Median closure of plantar ulcers reached 98.5% with the gel against 60.8% with the vehicle gel (p < 0.05).
In larger ulcers, over 100 square millimeters, median closure was 89.2% with the gel against −10.3% with vehicle, meaning those ulcers had grown. Among ulcers treated right after debridement, infections were also less common, 7% against 34%.
Two years earlier, a randomized trial with 86 evaluable patients with venous leg ulcers compared a 0.4% copper tripeptide cream, a silver sulfadiazine cream and a blank cream [4]. Only the silver cream shrank ulcers more than placebo; the copper tripeptide cream did not.
| Diabetic foot ulcers (1994) | Venous leg ulcers (1992) | |
|---|---|---|
| Product | GHK-Cu gel, daily | Copper tripeptide cream, 0.4% |
| Compared with | Vehicle gel, same wound care | Blank cream and silver sulfadiazine |
| Main result | Median closure 98.5% vs 60.8% | No better than blank cream |
| Other finding | Infections 7% vs 34% | Silver sulfadiazine beat both |
Different wounds heal by different routes, so both results can be true at once. What neither shows is a benefit from injecting GHK-Cu, which no trial here tested.
Hair
Hair is one of the most common claims, and the evidence is the thinnest. The 2008 review lists larger hair follicles and better hair-transplant success among its effects [1]. It describes no randomized trial of hair regrowth, and none appears among the studies here.
What is and is not known about peptides for thinning hair is set out in peptides for hair growth.
Inflammation and the rest
The anti-inflammatory claim rests on cell and animal work. The 2026 review describes suppression of the signaling molecules TGF-β and IL-6 in preclinical models [2].
No randomized human trial in this set measured inflammation as an outcome. The same is true of the liver, bone and nerve effects in the 2008 list.
The benefits, sorted by evidence
| Claimed benefit | Best evidence found | Tested in people? |
|---|---|---|
| Fewer wrinkles, firmer skin | Randomized trials of products applied to skin | Yes, on the skin only |
| Healing after laser resurfacing | Patient-reported satisfaction in a trial | Yes, on the skin only |
| Chronic wound healing | One positive and one negative randomized trial | Yes, mixed |
| Hair growth | Lab work; no randomized regrowth trial found | No |
| Lower inflammation | Cell and animal models | No |
| Liver, bone, nerve repair | Animal models | No |
The strongest case for GHK-Cu is on the skin, applied as a cream. Everything beyond that is a hypothesis worth testing, not a result. For topical amounts used in studies, see GHK-Cu dosage.
For another compound sold for skin, and how thin its topical evidence is by comparison, see NAD+ benefits for skin.