To analyze experimental data on the effect of various polyphenolic compounds on lifespan of mice, we approximated survival curves with the Gompertz model in its minimal form, which does not account for the heterogeneity of samples and the age-independent mortality. The plots of regressions of log0 (logarithm of the initial mortality) on  (the rate of aging) in series of control samples were used to assess the deviations of vectors directed from control to experimental data from the slopes of the control regressions. The analysis of published data suggests that resveratrol, polyphenol-containing grape skin extract, metformin, tocopherol, and the antioxidant SkQ1 do not produce changes beyond those possible upon comparing of different samples of a control population. The effect of the polyphenolic composition BP-C3 on female SHR mice is unique in being associated with a significant decrease in the rate of aging. The effect may be partly contributed to by the antioxidant properties of BP-C3. Its antioxidant capacity determined in vitro is comparable with that of established antioxidants, such as dihydroquercetin. Its effects in vivo include the ability to ameliorate reduction in the peroxide-decomposing activity of RBC lysates from male BALB/c mice treated with 5-fluorouracil.