Peptide Skincare & BeautySkin science and ingredient guides

Ingredient or product comparison

GHK-Cu Solution Comparison

Light blue (turquoise) 0.5–1.0% 5.5–6.5 Refrigerated 2–8°C, <30 days old Fully active Optimal for daily cosmetic use. Low cytotoxicity risk, maintains collagen stimulation Deep blue-green (teal) 1.5–2.0% 6.0–7.0 Refrigerated 2–8°C, <60 days old Higher potency

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

  • Light blue (turquoise)
  • 0.5–1.0%
  • 5.5–6.5
  • Refrigerated 2–8°C, <30 days old
  • Fully active
  • Optimal for daily cosmetic use. Low cytotoxicity risk, maintains collagen stimulation
  • Deep blue-green (teal)
  • 1.5–2.0%
  • 6.0–7.0
  • Refrigerated 2–8°C, <60 days old
  • Higher potency formulation. Effective for targeted remodeling, watch for irritation
  • Pale green-blue (faded)
  • <0.5% or degraded
  • 5.0–6.0
  • Stored >30 days or temp excursion
  • Partially degraded
  • Reduced efficacy. Copper dissociation likely, consider discarding
  • Brown-green
  • Oxidized copper
  • Variable
  • UV exposed or >25°C storage
  • Inactive or pro-inflammatory
  • Degraded. Apply this and you're delivering free copper ions, not functional complex
  • Clear (colorless)
  • 0% or unbound
  • <5.0 or >7.5
  • pH drift or never complexed
  • Inactive
  • Not GHK-Cu. Either pure peptide or total complex failure
  • Cloudy blue
  • Contaminated or precipitated
  • Unknown, likely compromised
  • Microbial growth or copper hydroxide precipitation. Discard immediately