The sparing effect of dose-fractionation was observed in adult male and female Drosophila melanogaster; 24-, 48-, 72-, and 96-h-old female flies, in general, show a higher recovery (increase in life-span) following dose-fractionation as compared to the males of the respective age. Recovery in 72-h-old females is maximal (31% increase in life-span) as against only 12% increase in the life span of the males.