Copper peptide questions we get asked all the time How often should you use it? Do you need to avoid the sun? If you're new, start once daily (evenings are great), Neurogan GHK Cu (Copper Peptide) Neck & Face Serum 1,200mcg (1 oz bottle) Copper Peptide Serum with 1% GHK Cu peptide, Argireline and Matrixyl 3000 Melatonin Hair Growth Serum GHK cu Stem Cells Scalp Hair Growth Serum STEMBOTANY Copper Peptide (GHK Cu) 2% Recovery Serum