After a year of using GHK Cu both topically and going deeper than topicals (under my doctor's care), the difference in my skin is not something I have to squint at in good Your body made this peptide every day until you turned 30. Then it stopped. GHK Cu (copper peptide) is a naturally occurring tripeptide discovered in 1973. At age 20, your plasma levels sit GHK Cu Injectable Team Wellcore GHK Cu Copper Peptide: Dosage, Before and After Results, and How It Works Perfect B