In tert-butyl hydroperoxide (t-BHP)-induced human granulosa-like tumor cells (n = 3), 40 μg/mL thymol increased cell viability by approximately 45%, restored superoxide dismutase, catalase, and glutathione peroxidase activities to nearly twice those of the model group, and reduced reactive oxygen species accumulation by about 35% (p < 0.05). This evidence concerns the gene CAT and neoplasm.