GHK Cu is one of my personal favorites for a lot of reasons, but I can say without a doubt that it's use effectively stopped and reversed, my receiving hairline. However, there are The Effect of the Human Peptide GHK on Gene Expression Relevant to Nervous System Function and Cognitive Decline Amazon.com: Neurogan GHK Cu + AHK Cu Hair Serum Pro Lightweight Scalp Serum with Dual Copper Peptides Daily Hair & Scalp Use, Cosmetic Product : Beauty & Personal Care 6 month GHK CU check in Main takeaway: skin transformation takes time. GHK CU peptide binds to copper and activates genes involved in wound healing, collagen synthesis, and skin remodeling. On the face, this translates GHK Cu as a multifunctional copper peptide: synthesis routes, process engineering and emerging applications Systems Microbiology and Biomanufacturing Springer Nature Link