GHK Cu vs NAD+: Which Longevity Peptide Should You Take or Stack? Copper Peptide Hair Growth Serum (GHK Cu & AHK Cu) GHK Cu (Copper Peptide) has emerged as one of the most promising regenerative peptides for hair restoration due to its ability to stimulate follicular activity, improve scalp circulation, reduce inflammation, and prolong the Say hello to your skin's new BFF GHK Cu is a powerful peptide that supports collagen production, speeds healing, improves hair growth, and helps fight visible signs of aging. This tiny molecule AHK Cu Copper Peptide Hair Growth Study (2007) Plain Language Summary Hairgenetix