Amazon.com: Neurogan GHK Cu (Copper Peptide) Neck & Face Serum 1,200mcg (1 oz bottle) : Beauty & Personal Care superPeptide 1% GHK Copper Peptide Serum Pure & Cimple GHK Cu Facial Serum Empower Pharmacy Not all Copper Peptides are created equal If you've tried copper peptides before and saw no change, here is why: Concentration and Stability. Most serums use a diluted solution that barely scratches ANAIRUI Copper Peptides GHK Cu Serum