I'm surprised I haven't seen this one here. After taking 2 sprays in each nostril for a month, I woke up with a swollen throat and hard to swallow. Thinking it was strep throat I went to doc and right away he said, "you have thrush". It was not a fun thing to have, it even went down my esophagus. The treatment for that was not fun either, sucking on big pills 5x a day for a week, they left the roof of my mouth sore. I think the manufacturer should pay for my side effect treatment, I was just an unsuspecting seasonal allergy sufferer.