A GHK Cu face serum appears blue because the active ingredient, GHK Cu (copper peptide), is naturally a blue colored powder, meaning its inherent color transfers to the serum when mixed in; this blue hue FDA highlights concerns with using dietary ingredient glutathione to compound sterile injectables FDA Glutathione Injections Private Label GHK Cu Copper Peptide Firming Anti Aging Skincare Sets Optimal Glutathione IV Dosage & Detox Benefits in Los Angeles Nebulized Glutathione IV Therapy Santa Monica Infuse Wellness Center