Last updated: May 18, 2026
What GHK-Cu is
GHK-Cu (also called copper peptide GHK-Cu or copper tripeptide-1) consists of three amino acids — glycine, L-histidine, and L-lysine — coordinated with a copper(II) ion. Discovered in 1973 by Loren Pickart, who identified that human plasma contains a factor that restores aged liver tissue function — that factor was GHK-Cu.
Mechanism of action
GHK-Cu’s most distinctive feature is its breadth of action. Gene expression analyses show it modulates approximately 4,192 human genes — over 30% upregulated, the rest downregulated. Key pathways include:
- Collagen and elastin synthesis — direct stimulation of fibroblast activity
- Antioxidant defense — increases SOD expression, glutathione, and copper-dependent enzymes
- Anti-inflammatory action — downregulates TNF-α and IL-6 pathways
- 5α-reductase inhibition — relevant to androgenetic alopecia
- VEGF expression — angiogenesis and wound healing
- p53 tumor suppressor restoration — relevant to longevity research
Endogenous decline with age
Plasma GHK-Cu measurements show a steep decline:
- Age 20: ~200 ng/mL
- Age 40: ~120 ng/mL
- Age 60: ~80 ng/mL
This roughly 60% decline correlates with reduced wound healing capacity, slower tissue regeneration, and the visible signs of skin aging. Restoring GHK-Cu via topical or injectable application is the basis of most therapeutic applications.
Topical applications — skin
Collagen synthesis
Multiple controlled studies show GHK-Cu serums (typically 1-3 ppm) increase dermal collagen synthesis. A 2007 study compared GHK-Cu to retinoic acid and found GHK-Cu produced significant increase in collagen, elastin, and glycosaminoglycan synthesis.
Wrinkle reduction
A 12-week study of GHK-Cu eye cream showed significant reduction in fine lines and increase in skin density vs vehicle control.
Hair growth applications
GHK-Cu inhibits 5α-reductase (the enzyme converting testosterone to DHT, the primary driver of androgenetic alopecia) and stimulates dermal papilla cell proliferation. Topical formulations (1-3 mg/mL) applied to scalp are studied for both male pattern hair loss and female pattern hair loss.
Wound healing
Original 1980s research established GHK-Cu’s wound-healing properties. Used in some clinical wound care formulations.
Dosing — topical, injectable, microneedling
- Topical serum: 1-3 ppm in cosmetic products; can apply 1-2x daily
- Microneedling delivery: Higher concentrations (0.1-0.5%) delivered through skin barrier
- Subcutaneous injection (research): 1-3 mg per dose, several times per week
Side effects and tolerability
Topical use is very well tolerated; mild redness occasionally reported. Injectable use is studied less in human cohorts but appears well-tolerated in available data.
Is GHK-Cu the same as copper peptides?<br />
GHK-Cu is the most-studied copper peptide. Other “copper peptides” exist (AHK-Cu, others) with different amino acid compositions and somewhat different effects.
Topical vs injectable — which works better?<br />
For skin remodeling and hair, topical application reaches the target tissue directly. For systemic effects (longevity), injection provides systemic levels. Topical is more practical and well-studied.
Is GHK-Cu FDA-approved?<br />
Cosmetic GHK-Cu formulations are sold commercially. Injectable GHK-Cu is sold as a research peptide; no FDA approval exists for therapeutic injectable use.
How fast does it work?<br />
Topical applications show measurable skin improvements within 4-12 weeks. Hair growth applications typically require 3-6 months for visible effects.