GHK-Cu side effects and results in studies
The one controlled human trial of GHK-Cu skin care products did not report adverse events in its abstract, and a microneedle study in pig skin observed no obvious skin irritation. In a mouse silicosis model the authors reported no significant systemic toxicity.
Are there GHK-Cu before and after results? The only controlled before-and-after measurement in people in these records is a small trial of skin care products applied after CO2 laser resurfacing. Thirteen patients completed it. Computer analysis and blinded evaluators found no significant difference between the GHK-Cu and non-GHK-Cu groups in redness, wrinkles or overall skin quality at 12 weeks, although patients in the GHK-Cu group rated their skin quality improvement higher on a questionnaire (P = .04).
The other measured results come from mice, rats and cells. In mice, GHK-Cu at 0.2 and 2 mg/kg reduced smoke-induced muscle loss and improved grip strength, reduced airway remodelling in an asthma model, and reduced lung fibrosis in a silicosis model. In rats, GHK in hydrogels shortened healing time of cut wounds. In cultured human fibroblasts, 1 × 10⁻⁹ mol/L GHK-Cu shortened population-doubling time.
Adverse-event reporting is thin. The laser trial abstract does not mention adverse events, the silicosis study reports no significant systemic toxicity in mice, and the microneedle study reports no obvious skin irritation. None of these is a safety study designed to find uncommon or long-term effects, and there are no human injection data in these records.
Adverse events reported
| Event | As reported | Source |
|---|---|---|
| Adverse events in people | Not stated in the abstract of the 13-patient topical trial | Miller TR et al. |
| Skin irritation | No obvious signs of skin irritation with GHK-Cu after microneedle pre-treatment (cell and porcine models) | Li H et al. |
| Systemic toxicity | No significant systemic toxicity reported in silicosis mice given GHK-Cu | Bian Y et al. |
Outcomes measured
| Outcome | Result as reported | Source |
|---|---|---|
| Post-laser redness (erythema), human | No significant difference between groups | Miller TR et al. |
| Wrinkles and skin quality, objective, human | No significant difference between groups at 12 weeks | Miller TR et al. |
| Patient-rated skin quality, human | Significantly higher with GHK-Cu (P = .04) | Miller TR et al. |
| Grip strength, smoke-exposed mice | 175.5 g untreated vs 257.6 g (0.2 mg/kg) and 339.1 g (2 mg/kg) | Deng M et al. |
| Airway remodelling, asthma mice | Less peribronchial collagen and mucus secretion | Zhang Q et al. |
| Lung inflammation and fibrosis, silicosis mice | Reduced | Bian Y et al. |
| Scald wound healing time, mice (liposomes) | Shortened to 14 days post injury | Wang X et al. |
| Fibroblast population-doubling time, cells | Faster than untreated controls | Pollard JD et al. |
What the studies don't show
These records contain no human safety data for injected GHK-Cu and no study longer than 12 weeks. The one human trial is small and its objective measures were negative, and the animal findings cannot be read as effects in people.