Is it harmful to use toilet paper during menstruation?
Menstruation, commonly known as a period, typically poses no significant health risks when high-quality toilet paper is used briefly in emergencies and changed frequently. However, replacing sanitary pads with toilet paper throughout the entire period or using low-quality toilet paper may pose health risks. If concerned, it is advisable to consult a healthcare professional in advance. Detailed analysis is as follows:

During the very beginning or end of menstruation, when blood flow is minimal and sanitary pads are unavailable, temporarily using toilet paper from reputable brands—free of irritating ingredients and with a soft texture—can be acceptable. Changing it every 1–2 hours and keeping the external genital area dry ensures the area isn't exposed to prolonged moisture, minimizing bacterial growth and posing no harm to the body, effectively managing light menstrual flow.
However, if toilet paper is used throughout the entire menstrual period or if cheap, rough, or unhygienic toilet paper is used, potential problems arise. Toilet paper has significantly lower absorbency than sanitary pads, increasing the risk of leakage and failing to keep the external genital area dry, thus promoting bacterial growth. Low-quality toilet paper may contain impurities or harmful substances; repeated contact with the external genital area can cause itching, redness, swelling, and even lead to gynecological conditions such as vulvitis or vaginitis. Therefore, this practice is not recommended.
During menstruation, it is best to use sanitary pads that meet hygiene standards, selecting products with appropriate absorbency based on blood flow. If discomfort occurs in the genital area, discontinue use of the suspected product immediately and seek medical evaluation if necessary.