GHK Cu vs NAD+: Which Longevity Peptide Should You Take or Stack? Anybody know the correct way of using ahk cu? Do I mix with bac water and inject into abdomen? The GHK Cu pen works. But needles at home were never the answer. We took the same clinically backed copper peptide complex and put it into a serum you can use in 30 seconds, Peptide Dosing Schedule and Guidelines PDF Dose (Biochemistry) Chemistry