Peptide Skincare & BeautySkin science and ingredient guides

Ingredient or product comparison

Is GHK-Cu Safe According to Studies?: Full Comparison

Topical (intact skin) 0.5%–5% 1.8–3.2% (mild dermatitis) None detected (<2 µg/dL change) Yes. 12-week trials with 6-month follow-up Safest route with decades of validation; minimal risk profile Topical (open wounds) 1%–5% 4–6% (transient erythema) 8–12 µg/dL a

This source-based comparison does not add ratings or recommend a winner.

  • Topical (intact skin)
  • 0.5%–5%
  • 1.8–3.2% (mild dermatitis)
  • None detected (<2 µg/dL change)
  • Yes. 12-week trials with 6-month follow-up
  • Safest route with decades of validation; minimal risk profile
  • Topical (open wounds)
  • 1%–5%
  • 4–6% (transient erythema)
  • 8–12 µg/dL above baseline
  • Limited. 8-week wound healing studies
  • Safe within physiological copper homeostasis; monitor in hepatic impairment
  • Subcutaneous injection
  • 0.5mg–10mg per site
  • 4–31% (dose-dependent induration)
  • None at ≤5mg; transient at 10mg
  • Limited. Phase I safety only, no long-term
  • Intravenous infusion
  • Not clinically tested
  • No human data
  • Unknown
  • None
  • Insufficient data; not recommended outside controlled trials
  • Oral supplementation
  • 1mg–5mg daily
  • 8–12% (GI upset, nausea)
  • Minimal (bound form resists absorption)
  • None. No published trials
  • Poor bioavailability; safety unclear; peptide likely degraded in GI tract