Introduction. Circadian rhythms are deeply rooted in the vital activity of almost all organisms. The use of artificial lighting in modern society disrupts the natural rhythm of human life and is a risk factor for the development of various diseases. Given the role of melatonin in the regulation of circadian rhythms, it was decided to study its content in buccal epithelium cultures of people of different age groups, as well as methods for correcting deficiency states in order to modify existing disorders. The purpose of the study is to study the effect of the pineal gland polypeptide complex and the AEDG peptide on circadian rhythms in order to reverse biological age. Materials and methods. The excretion of 6-sulfatoxymelatonin in the urine of middle-aged individuals with a shift work pattern was studied. Patients with reduced melatonin-forming function were divided into 3 subgroups: placebo, with sublingual use of the AEDG peptide and sublingual use of the pineal gland polypeptide complex. 6-sulfatoxymelatonin was determined by enzyme immunoassay. To assess the statistical homogeneity of several samples, nonparametric procedures of one-way ANOVA (Kruskal-Wallis test) were used. Results and discussion. Against the background of the use of the pineal gland polypeptide complex and the AEDG peptide, the level of 6-sulfatoxymelatonin excretion was statistically significantly higher compared to this indicator before the start of treatment and the placebo group. The subjects showed a pronounced positive dynamics of the psychoemotional and general physical condition. Conclusion. The AEDG peptide and the pineal gland polypeptide complex have a complex effect on the body at the level of gene expression and protein synthesis, regulating circadian rhythms and slowing down cellular aging. Taking these peptides contributed to the restoration of the melatonin-forming function of the pancreas to the age norm, and also influenced the subjective assessment of the well-being of patients and improved their quality of life, reversing the manifestations of premature aging of the body. The use of the pineal gland polypeptide complex and the AEDG peptide can be recommended for further study as geroprotective agents, as well as means for correcting sleep-wake cycle disorders in various age groups.