Topical makes the most sense for: Facial skin texture, fine lines, hydration Scalp application for localized hair growth Scar treatment or post-procedure recovery on a specific area Patients who want to fold GHK-Cu into an existing skincare routine Injectable makes the most sense for: Systemic wound healing (especially internal or in areas you can't easily apply cream) Joint and connective tissue support (topical simply can't penetrate deep enough) Broader anti-aging goals beyond the skin surface Patients already running other injectable peptide protocols (CJC-1295/ipamorelin, BPC-157, TB-500) Here's the thing: for joints specifically, there's no argument
At maintenance doses of 2.0mg or 2.4mg, the volume increases significantly
Journal of Endocrinology and Metabolism , 4 (3), 64-77
Another PubMed review highlights the regenerative and protective actions of GHK-Cu, including gene regulation relevant to skin repair, wound healing, and cell-protective pathways
There's a lot of articles about them
BPC 157 also supports collagen production but is more recognized for its effects on the gastrointestinal system