AHK-Cu (Alanine-Histidine-Lysine Copper) vs GHK-Cu
A neutral, side-by-side comparison of two anti-aging & longevity peptides — their mechanisms, dosing ranges, administration routes, side effects, and research evidence. For research and educational purposes only.
AHK-Cu (Alanine-Histidine-Lysine Copper)
Copper-chelating tripeptide structurally related to GHK-Cu but optimized for scalp and hair follicle applications. AHK-Cu activates hair follicle stem cells and prolongs the anagen (active growth) phase, making it a key research compound for androgenetic alopecia and diffuse hair loss. Used topically as an alternative or complement to minoxidil and finasteride.
Full profileGHK-Cu
GHK-Cu is a naturally occurring copper peptide found in human plasma, saliva, and urine. It plays a role in wound healing, skin regeneration, and anti-inflammatory signaling. Levels decline significantly with age, which has driven interest in topical and injectable supplementation.
Full profile| AHK-Cu (Alanine-Histidine-Lysine Copper) | GHK-Cu | |
|---|---|---|
| Category | Anti-Aging & Longevity | Anti-Aging & Longevity |
| Also known as | AHK copper peptide, Ala-His-Lys copper, hair growth copper peptide, AHK-copper complex | Copper Peptide GHK-Cu, Glycyl-L-histidyl-L-lysine copper, Copper Tripeptide-1 |
| Evidence | Research-stage | Research-stage |
| Dosing range | 0.1%–1% %, Daily topical application (scalp) | 1mg–3mg mg, daily to every other day (injectable); twice daily (topical) |
| Administration | Topical (scalp serum/solution), Subcutaneous (microneedling-assisted delivery) | Subcutaneous injection, Topical application (cream, serum — most common consumer use), Intradermal injection (skincare clinics) |
| Key side effects | Mild scalp irritation, Contact dermatitis (rare), Temporary scalp redness or tingling, Transient scalp shedding at initiation (shedding phase) | Injection site redness (transient), Mild skin irritation with topical (typically resolves with reduced frequency), Rarely reported: metallic taste (with injectable use at higher doses) |
| Cited sources | 2 references | 4 references |
Key differences
- Administration: AHK-Cu (Alanine-Histidine-Lysine Copper) — Topical (scalp serum/solution), Subcutaneous (microneedling-assisted delivery); GHK-Cu — Subcutaneous injection, Topical application (cream, serum — most common consumer use), Intradermal injection (skincare clinics).
- Dosing units differ: AHK-Cu (Alanine-Histidine-Lysine Copper) is dosed in %, GHK-Cu in mg — they operate at different scales.
- Frequency: AHK-Cu (Alanine-Histidine-Lysine Copper) is typically Daily topical application (scalp); GHK-Cu is daily to every other day (injectable); twice daily (topical).
- Research depth: this profile cites 2 sources for AHK-Cu (Alanine-Histidine-Lysine Copper) vs 4 for GHK-Cu.
How each works
AHK-Cu (Alanine-Histidine-Lysine Copper)
AHK-Cu activates β-catenin/Wnt signaling in dermal papilla cells and promotes VEGF expression around hair follicles. Studies demonstrate extended anagen phase duration, increased follicle size, and upregulation of hair growth factors in treated scalp tissue. The copper component supports tyrosinase activity for follicle pigmentation and metalloenzymes involved in extracellular matrix remodeling around follicles.
GHK-Cu
GHK-Cu has been studied for its ability to stimulate collagen, elastin, and glycosaminoglycan synthesis, promote wound healing, and exhibit antioxidant and anti-inflammatory effects. Gene-expression work by Pickart and colleagues found GHK altered expression (>50% up or down) in roughly 32% of assayed human genes — the basis of the widely-cited '~4,000 genes' figure. Its evidence is strongest for in-vitro and topical/cosmetic use; robust human trials of injectable/systemic GHK-Cu are lacking.
This comparison aggregates public research and structured profile data for informational purposes only. It is not medical advice and does not recommend either compound for human use. Consult a qualified healthcare provider before considering any peptide.