Researchers say menstrual blood testing could offer a simple, non-invasive alternative to cervical 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 instead of attending a clinic.
Researchers in China compared menstrual blood samples with clinician-collected cervical samples.
The study involved more than 3,000 women aged 20 to 54 with regular periods.
Findings were published in BMJ.
The pad-based test detected serious cervical cell changes with 94.7% sensitivity.
This matched the accuracy of clinician-collected samples.
Specificity was slightly lower, but negative results were equally reliable.
Researchers said the test could replace or support existing screening methods.
They highlighted its potential to reach women who skip current screening.
Cancer Research UK welcomed the innovation but urged caution.
Experts said larger and more diverse trials are still needed.
Eve Appeal said choice could improve screening uptake.
They noted the test would not suit everyone, including menopausal women.
