This monograph highlights the gerontological aspects of the peptide regulation of gene expression. It focuses on the mechanisms of the geroprotective action of peptides related to chromatin activation, increase in telomerase enzyme activity, and elongation of telomeres in different cells. A key role in the initiation of the biological activity of peptide is its interaction with DNA which provides genetic stability and a normalization of the age-related metabolic shifts. Study of the genetic mechanisms of peptide action suggests a new concept which most comprehensively reflects on the evolutionary biological role peptide plays in the organism. The impact of peptides on the expression and structure of genes opens a new gate for the prevention of premature aging and age-related pathology which appears to be most promising in pharmacogenomics. This monograph narrates not only the theoretical aspects and experimental data, but also outlines new approaches to the prevention of aging and age-related pathology, thus addressing a wide readership of gerontologists, geneticists, molecular biologists, biochemists, and pharmacologists alike.