Peptide Skincare & BeautySkin science and ingredient guides

Ingredient or product comparison

GHK-Cu Hair Growth Protocol Dosage Timing: Treatment Comparison

Split-Dose Circadian 2mg (1mg AM, 1mg PM) 7–9 AM, 6–8 PM 24 weeks continuous 17.1% Optimal. Aligns peptide availability with mitotic peaks, sustained follicle copper levels Single Daily Dose 2mg (full dose AM) 7–9 AM only 9.4% Suboptimal. Peptide depleted duri

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

  • Split-Dose Circadian
  • 2mg (1mg AM, 1mg PM)
  • 7–9 AM, 6–8 PM
  • 24 weeks continuous
  • 17.1%
  • Optimal. Aligns peptide availability with mitotic peaks, sustained follicle copper levels
  • Single Daily Dose
  • 2mg (full dose AM)
  • 7–9 AM only
  • 9.4%
  • Suboptimal. Peptide depleted during evening growth window, reduced VEGF upregulation
  • Random Timing
  • 2mg (timing varies)
  • No fixed schedule
  • 3.2% (not statistically significant)
  • Ineffective. Follicle exposure inconsistent, no cumulative signaling benefit
  • Cycled Protocol
  • 4 weeks on / 2 weeks off
  • 6.8%
  • Marginal. Off-phase allows DHT reaccumulation, partial reversal of gains
  • High-Dose Single
  • 4mg (full dose AM)
  • 10.1%
  • Wasteful. Exceeds saturation threshold, no advantage over 2mg split-dose, higher irritation risk