GHK-Cu enhances collagen synthesis (types I and III), upregulates glycosaminoglycan (GAG) production, and modulates the balance between matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs)-thereby both promoting extracellular matrix (ECM) formation and controlling ECM degradation
This effect makes glutathione especially appealing for those with uneven skin tone, lingering sun damage, or pigmentation concerns often exacerbated by the intense summer sun or holiday stress
At 9mg weekly: Nausea: 38.1% Diarrhea: 34.7% Constipation: 21.8% Vomiting: approximately 15-20% At 12mg weekly: Nausea: 43.2% Diarrhea: 33.1% Constipation: 25.0% Vomiting: approximately 18-22% These numbers look concerning, but context matters
The strongest support comes from clinical evidence focused on treating vitamin B12 deficiency, not from general wellness claims What science supports The NIH Fact Sheet for Health Professionals shows that intramuscular B12 injections are effective at raising blood B12 levels and correcting deficiency
Decreased neurogenesis after cholinergic forebrain lesion in the adult rat