GHK Cu Hair & Scalp Serum 2400mg 4% Less Shedding Neurogan Neurogan Health Defy GHK Cu (glycyl L histidyl L lysine) is a naturally occurring copper binding peptide found in human plasma. As levels decline with age, so may its support of the biological processes involved in collagen production, skin ENHANCED EXTENDS PEPTIDE PLATFORM WITH TOPICAL GHK CU, FORMULATED UNDER MEDICAL COMMISSION OVERSIGHT Enhanced The Effect of the Human Peptide GHK on Gene Expression Relevant to Nervous System Function and Cognitive Decline