For topical use, transient local reactions redness, stinging, burning, or itch are the expected category and are exactly what the ongoing Phase 2 trial is set up to measure (NCT07437586)
2017) for protocol-specific concentrations
They also are sensitive to environmental conditions and can change chemical composition if stored at the wrong temperatures or shaken too vigorously, increasing the risk of an immune response or decreasing their effectiveness
To learn more about what copper peptides are and their specific GHK-Cu benefits, exploring a dedicated comparison guide is highly recommended
Increased collagen levels, whether through supplements, a balanced diet, or skincare treatments, can help you preserve your skin's structural integrity and enjoy a beautiful, firm complexion for years to come