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Skin & Hair comparison

GHK-Cu vs Melanotan II

An educational, source-based comparison of GHK-Cu and Melanotan II — how each peptide works, what it's researched for, and what to know before going deeper.

Skin · Regeneration
GHK-Cu

Copper peptide researched for skin regeneration and collagen support.

Mechanism

A naturally occurring tripeptide (Glycyl-L-Histidyl-L-Lysine) that forms a complex with copper(II) ions. Research indicates it modulates ~4,000 human genes, downregulating those associated with inflammation and tissue breakdown while upregulating genes tied to collagen synthesis, antioxidant defense, and stem cell activation.

Research areas
  • Collagen and elastin synthesis
  • Wound healing
  • Hair follicle stimulation
  • Skin barrier and antioxidant capacity
  • Anti-glycation in dermal fibroblasts
Considerations
  • Topical formulations have decades of cosmetic safety data; injectable use is less studied.
  • Copper sensitivity is rare but possible.
  • Compounded injectable GHK-Cu is not FDA-approved.
Full GHK-Cu profile →
Pigmentation · Melanocortin
Melanotan II

Melanocortin agonist researched for tanning response and libido.

Mechanism

A non-selective melanocortin receptor agonist that stimulates eumelanin production via MC1R and influences appetite, libido, and erectile function via MC3R/MC4R.

Research areas
  • UV-independent pigmentation
  • Erythropoietic protoporphyria (related compound, afamelanotide)
  • Sexual function (overlap with PT-141)
Considerations
  • Not FDA-approved.
  • Risk of new or changing nevi — dermatologic monitoring is essential.
  • Common side effects: nausea, flushing, spontaneous erections, appetite suppression.
Full Melanotan II profile →

GHK-Cu vs Melanotan II — Key differences

  • Class: GHK-Cu is classified as Skin · Regeneration, while Melanotan II is Pigmentation · Melanocortin.
  • Primary research focus: GHK-Cucollagen and elastin synthesis; Melanotan IIuv-independent pigmentation.
  • Tag: Skin · Anti-aging vs Skin · Pigmentation.

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