Is topical GlycylLhistidylLlysine copper (GHKCu) safe for adults, and what are the risks, contraindications, and considerations for systemic use, pregnancy, lactation, and children? What is Wilson disease? It's a rare condition where excess copper builds up in the body, affecting the function of the liver, brain, and other organs. Early signs and symptoms Current and Emerging Issues in Wilson's Disease New England Journal of Medicine Does GHK Cu Really Work? 40 Years of Research Reviewed