The Effect of the Human Peptide GHK on Gene Expression Relevant to Nervous System Function and Cognitive Decline Safety and Efficacy of Approved and Unapproved Peptide Therapies for Musculoskeletal Injuries and Athletic Performance[v3] Preprints.org Journal of Neuroscience Research JNR Neuroscience Journal Wiley Online Library Therapeutic exploration of biased ligands at class A G protein coupled receptors over the past 20 years ScienceDirect 16. Receptor Regulation Principles of Pharmacology Study Guide The Effect of the Human Peptide GHK on Gene Expression Relevant to Nervous System Function and Cognitive Decline