Answered by Shaykh Yūsuf Badāt
Is it permissible to swallow saliva while fasting? Does it break the fast?
In the Name of Allāh, Most Merciful, Most Compassionate
Jazāk Allāh Khayr/ Thank you for your question.
Swallowing one’s own saliva will not invalidate the fast. (See: Badā’i al Ṣanā’i)
The act of one deliberately gathering, collecting and swallowing one’s own saliva, to quench thirst, while fasting, is disliked – makrūh – (See: Marāqī al-Falāḥ)
And Allāh Knows Best
This answer was collected from Mathabah.org. It’s an Islamic educational institute based in Canada. The questions are generally answered by Sheikh Yusuf Badat and Sheikh Omar Subedar.