Amazon.com: Neurogan GHK Cu Copper Peptide Hair & Scalp Serum 2400mg, 4% Copper Peptides Fast Absorbing, Water Based Formula for Hair Softness & Shine Cosmetic Dry Scalp Moisturizer Spray, Made in USA : GHK Cu Aesthetics Infinity Medical Institute How long will a 50 mg supply of GHKCu last when dosing 2 mg daily for five consecutive days followed by two days off each week? 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),