Will flonase help with tinnitus?

Possibly: Flonase is a nasal steroid that is frequently used to treat allergic rhinitis. Treating allergic rhinitis can, in turn, help with eustachian tube function. One treatable cause of tinnitus is eustachian tube dysfunction which effectively creates a vacuum or negative pressure in the middle ear. If tinnitus from hearing loss or other causes, it is not likely to make much difference for the ringing.