The Ruling on using Tablets to delay the Onset of the Menstrual Period
Question :
There are tablets which prevent (i.e. delay) the onset of a woman's monthly period; is it permissible to use them just at Hajj time, if she fears its commencement (during the Hajj)?
Answer:
It is permissible for a woman to use tablets to delay her period at Hajj time, if she fears that the menstrual period will begin. But this should be undertaken only after consulting a medical specialist with regard to its safety. Likewise, they may be used in Ramadhan, if she likes to fast with the people.
Source:
The Permanent Committee
Fatawa Islamiyah, Vol. 2 Page 115