Question: I have a sister who is going to perform pligrimage and some people advised her to take something to prevent the monthly habit and she desires to know if it is right or not to do so.
Fatwa: All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
It is permissible for your sister to delay her monthly period in order to perform all the rituals of Hajj (Pilgrimage), especially the Tawaf (Circumambulation) of Hajj. This permission: 1 - applies if her period will prevent her from being accompanied by her Mahram, thus preventing her from travel. 2- applies if she will suffer financial or material loss resulting from having to delay or cancel her travel. 3 - applies if the occurrence of her period could cause legal (Visa, immigration, travel) problems during the Hajj period. Moreover, Muslim scholars set a condition that using this medicine should not be something that could cause any harm to woman.
Allah Knows best.