Background: Exposure to titanium dioxide nanoparticles (TiO₂ NPs) that are widely used in food, medicine, sunscreen products and cosmetics is reported to cause ovarian damage and lower fertility in animals. However, the potential effects of TiO₂ NPs application on premature ovarian failure (POF) have rarely been evaluated to date.
Methods: In this study, female mice were continuously exposed to TiO₂ NPs at doses of 2.5, 5 or 10 mg/kg via gavage instillation for 30 days, and investigated the serum hormones and autoimmunity markers associated with POF. 
Results: Exposure to TiO₂ NPs resulted in POF, reductions in the levels of estradiol, progesterone and inhibin B and increases in luteinizing hormone, follicle-stimulating hormone, follicle-stimulating hormone/luteinizing hormone ratio, anti-Müllerian hormone, thyroid-stimulating hormone, free triiodothyronine, free tetraiodothyronine, anti-nuclear antibody and anti-thyroid peroxidase antibody levels in serum. 
Conclusion: Exposure to TiO₂ NPs induced POF triggered by alterations in hormones and autoimmunity markers. Our findings highlight the necessity for significant caution in handling and usage of TiO₂ NPs by female consumers.
Keywords: titanium dioxide nanoparticles, mice, premature ovarian failure, serum hormone levels, autoimmunity levels