Peptide Skincare & BeautySkin science and ingredient guides

Ingredient or product comparison

GHK-Cu for Dark Circles Under Eyes Research: Product Comparison

Pre-mixed aqueous serum 0.5–1% (degraded to ~0.2% after 30 days) Poor. Oxidizes within 4–6 weeks of opening Convenient but compromised potency Acceptable for initial trials; replace monthly Anhydrous silicone suspension 1–2% (stable for 90+ days) Excellent. Co

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

  • Pre-mixed aqueous serum
  • 0.5–1% (degraded to ~0.2% after 30 days)
  • Poor. Oxidizes within 4–6 weeks of opening
  • Convenient but compromised potency
  • Acceptable for initial trials; replace monthly
  • Anhydrous silicone suspension
  • 1–2% (stable for 90+ days)
  • Excellent. Copper protected from oxidation
  • Apply to dry skin; may require emulsifier
  • Best balance of stability and usability
  • Lyophilized powder (reconstitute fresh)
  • 2–5% (100% potency at mixing)
  • Optimal. No degradation until reconstituted
  • Requires sterile technique; 14-day use window
  • Gold standard for research-grade application
  • Oil-based formulation
  • 0.5–1% (stable 60–90 days)
  • Good. Lipid environment slows oxidation
  • Works under occlusive moisturizers
  • Reliable for sustained protocols