This book aims to provide scientific information about hormones. Hormones are chemical compounds that transmit specific information between organs and thus regulate the body's work. As a group of biologically active signaling molecules, they belong to the four main groups of organic chemical compounds. The 36 chapters present the characteristics of exemplary hormones. The prepared monograph is a description of the most popular hormones. In this volume, one can read about the biochemical pathways of adrenaline, adrenocorticotropic hormone (ACTH), aldosterone, antidiuretic hormone (vasopressin), cholecystokinin, corticosteroid, corticotropin releasing hormone (CRH), cortisol, endocrine disorders, endocrine system, epinephrine, erythropoietin, estrogen, follicle-stimulation hormone (FSH), ghrelin, glucagon, gonadotropin releasing hormone (GnRH), growth hormone (GH), growth hormone releasing hormone (GHRH), hepcidin, human chorionic gonadotropin-?, humoral factors, importance of a correct hormonal balance for the psychological well-being of women, insulin, insulin-like growth factor (IGF), luteinizing hormone (LH), insulin, oxytocin, parathyroid hormone (PTH), progesterone, prolactin, thyroid-stimulating hormone (TSH), serotonin, thyroid hormone, thyrotropin releasing hormone (TRH) and prolactin.