The menstrual cycle changes with age, but the menopause and the time leading up to it can particularly throw its patterns out of sync.
Feeling that previous studies on the menstrual cycle were small and lacked a diversity of ages, Adam Cunningham at the period tracker app Flo in London and his colleagues analysed data that was self-reported by 19 million app users, aged between 18 and 55, from 2022 to 2023.
Overall, the team found that cycles became shorter and more variable…