Hi @blarney2020 and welcome to Connect. I can only imagine what it feels like to have anxiety from these internal tremors while on Synthroid.

Fellow Connect members @hope58 @jewles63 and @khali have experience with internal shakiness and may be able to offer their support.

I also wanted to share this link of the Diabetes & Endocrine System group where you can find Connect members talking about thyroid conditions and synthroid use: https://connect.mayoclinic.org/group/diabetes-and-endocrine-problems/

Back to you @blarney2020 how long have you been experiencing the internal shakiness? Based on what you said in your post, would it be accurate to say this is a recent development?