Histomorphological studies were conducted to evaluate the effects of NS-Oil (NS) on ovarian toxicity induced by cyclophosphamide in female rats. The research aimed to assess the histological changes in ovarian tissue and correlate these findings with alterations in serum gonadotropin levels. The experimental design involved three (3) experimental groups treated with cyclophosphamide, NS-Oil oil, or a combination, with control group for comparison. Histological assessments of ovarian sections were performed to analyze structural integrity, follicular development, and toxicity signs, while serum samples were analyzed for estradiol, progestin levels.Cyclophosphamide administration significantly disrupted ovarian architecture, reducing follicle count and causing follicular degeneration. Conversely, NS-Oil oil treatment exhibited protective effects, restoring normal histological features and improving gonadotropin levels. Image J software, calibrated with a table micrometer, was used to measure diameters of follicles, follicular cells, and oocytes. Primary, secondary, and tertiary follicles were classified according to Oktay et al. (2017). Body weight showed no significant difference across groups, but ovarian weight decreased in cyclophosphamide-treated groups compared to controls (p < 0.05). However, ovarian weight increased dose-dependently in NS-Oil-treated groups (p < 0.05).Cyclophosphamide reduced ovarian cortex and medulla volumes (p < 0.05), while NS-Oil treatment increased these volumes (p < 0.05). Pre-antral and antral follicle counts decreased with cyclophosphamide but increased following NS-Oil treatment (p < 0.05). Atretic follicle counts decreased in both cyclophosphamide and NS-Oil-treated groups (p < 0.05). The diameters of pre-antral and antral follicles, as well as follicular cells, decreased with cyclophosphamide but increased post NS-Oil treatment (p < 0.05).These results suggest that NS-Oil may offer a therapeutic strategy to mitigate ovarian damage associated with cyclophosphamide treatment, highlighting its potential role in preserving reproductive health in patients undergoing chemotherapy. Further investigations are warranted to elucidate the underlying mechanisms of action and the efficacy of NS-Oil in clinical settings.