It is not recommended for a woman to take pills to delay menstruation with the intention of catching the full month of Ramadan fasting. It is Allah, the Creator and Sovereign Lord, Who has created women with this nature, and it is He in His infinite wisdom Who has decreed that women must forego Prayer and fasting while menstruating. So it is only most apt for women to surrender to the decree of Allah.
Sheikh Ahmad Kutty, a senior lecturer and Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, states: According to the best of my knowledge and understanding, it is not recommended for women to take pills to delay menstruation with the intention of catching the full month of Ramadan fasting. For as the Prophet (peace and blessings be upon him) told his beloved wife `A’ishah—who had accompanied him in his final pilgrimage and who had been apparently distressed by the fact that because of the onset of menses she was unable to perform `Umrah like everyone else in the group—, “(There is nothing to be distressed about) since it is something that Allah has decreed on the daughters of Adam!” In other words, menses is a natural part of a woman’s life, and she needs to organize her life around it. On closer reflection we can see that it is Allah, the Creator and Sovereign Lord, Who has created women with this nature, and it is He in His infinite wisdom Who has decreed that women must forego Prayer and fasting while experiencing menstruation. So, it is only most apt for women to surrender to the decree of God and forego Prayer and fasting while menstruating.
Furthermore, there is no reason for women to be distressed by the fact that they are missing the rewards accruing from Prayer and fasting, for Allah in His infinite mercy has certainly appointed for them ample substitutes to make up for such deficiencies. In other words, they will have sufficiency of rewards in whatever good works they can possibly be engaged in.
Before concluding, it is important to point out that the pills that interfere with women’s natural rhythms and cycles must never be taken lightly, for as it has been the case with such interferences, nobody can fully assess the long-term adverse effects of such actions. It is, therefore, only befitting us as humans to choose freely what God in His supreme wisdom has chosen for us.