Researchers say menstrual blood testing could provide a convenient alternative to cervical cancer screening.
A sanitary pad fitted with a sample strip can detect human papillomavirus, the main cause of cervical cancer.
Women could use the test at home, avoiding invasive clinical procedures.
The study, published in BMJ, analysed data from more than 3,000 women in China.
Researchers compared menstrual blood samples with clinician-collected cervical samples.
The pad-based test detected serious cervical abnormalities with similar accuracy.
The menstrual test showed 94.7% sensitivity for detecting high-grade cell changes.
Clinician-collected samples showed a sensitivity of 92.1%.
Both methods performed equally well at ruling out disease after negative results.
Researchers said the approach could improve screening access for women who avoid appointments.
Cancer Research UK called the findings encouraging but said more research was needed.
The Eve Appeal welcomed the potential for gentler screening options.
Experts stressed the test would not suit everyone, including menopausal women.
