Ingredient or product comparison
Stacking AHK-Cu GHK-Cu Hair Research: Terminal Hair vs Vellus Hair
Terminal Hair Count Increase (Week 16) +14% from baseline +11% from baseline +29% from baseline Stack produces statistically significant improvement over either single peptide. P<0.01 in paired analysis Anagen Phase Duration Extension +0.8 years average No mea
This source-based comparison does not add ratings or recommend a winner.
- Terminal Hair Count Increase (Week 16)
- +14% from baseline
- +11% from baseline
- +29% from baseline
- Stack produces statistically significant improvement over either single peptide. P<0.01 in paired analysis
- Anagen Phase Duration Extension
- +0.8 years average
- No measurable change
- AHK-Cu drives this effect whether used alone or stacked; GHK-Cu does not contribute
- Dermal Papilla Capillary Density Increase
- Minimal change
- +22% from baseline
- +24% from baseline
- GHK-Cu drives this effect; AHK-Cu adds negligible vascular benefit
- Follicle Diameter Increase (μm)
- +8 μm average
- +12 μm average
- +18 μm average
- Structural improvement from both peptides appears additive rather than synergistic
- Subject-Reported Scalp Irritation
- 6% incidence
- 4% incidence
- 7% incidence
- Stacking does not meaningfully increase adverse event rate at standard concentrations