The author touches upon the little studied and insufficiently covered in the domestic literature problem of hormone biorhythms in phylogenetically different" animal and human species, the relationship between circadian hormone rhythms and physiological functions, issues of age-related hormone chronology and immune system reactivity. Noteworthy are the author's attempts to detect the correction of some types of endocrine pathology with biorhythms of leading hormonal systems, for example, hypothalamic-pituitary-adrenal, etc.