再强的女人也敌不过大姨妈
[zài qiáng de nǚ rén yĕ dí bù guò dà yí mā]
This phrase humorously acknowledges even the strongest woman can be laid low by menstrual periods ('Big Aunt'). It’s commonly used in Chinese net culture for sympathizing with female discomforts related specifically to monthly cycles and emphasizing common shared experience.