My FGFR treatment last year gave me some awful side effects. Thankfully, I went in for my routine thyroid function test. My gosh. My numbers were on the floor. Boy, did I pay for that. Got it back up with thyroid meds, but I wish I had been told by any of my physicians and PA’s that that is rather common. I don’t then understand why they don’t do routine testing of your thyroid function when they do the blood draws. Look up the side effects! Devastating.