For motor neuron count, spinal cords from anesthetized rats were collected and post-fixed for 12 hours in 4% PFA
Results maintenance requires ongoing or periodic use - stopping treatment leads to gradual regression over 2-6 months as new collagen formation stops and natural aging resumes
However, many other places have simplified the process

showed increased epidermal and dermal thickness, skin hydration, skin elasticity, skin contrast, and collagen I synthesis A trial with 41 women applying GHK-Cu eye cream for three months reported reduced lines and wrinkles, improved skin density, and increased skin thickness, outperforming both placebo and vitamin K cream Comparable studies show wrinkle volume reductions around 60-70%, attributed to enhanced collagen cross-linking and decorin synthesis Key Benefits for Product Claims Formulators can support the following claims when incorporating GHK-Cu: Firmer feel and improved skin firmness Smoother skin texture with reduced wrinkles More even tone and enhanced radiance Improved skin hydration and barrier function Powerful antioxidant protection against environmental stressors and reactive oxygen species Reduction of visible redness Effects are gradual rather than instant, relying on consistent use to deliver meaningful improvements in skin density and overall appearance

Even if LBP most likely evaluates the transcellular rather than paracellular pathway, a recent study demonstrated a significant correlation between LBP levels and the LMR in normal weight and obese subjects (60)
P = 1.28e-02), MIP-1 (r = 0.5894