Researchers say menstrual blood testing could provide a simple alternative to cervical cancer screening.
A sanitary pad with a sample strip can detect Human papillomavirus, which causes most cervical cancers.
Scientists in China compared pad-collected menstrual blood with clinician-taken cervical samples.
The study involved more than 3,000 women aged 20 to 54 with regular periods.
Results published in BMJ showed similar accuracy between both methods.
Menstrual blood detected serious cervical abnormalities with 94.7% sensitivity.
Researchers said the test could improve access for women who avoid clinic screenings.
Cancer Research UK welcomed the findings but urged further trials.
Eve Appeal said offering screening choices could save lives.
Experts cautioned the method may not suit everyone, including postmenopausal women.
