Synthroid side effects

I was on Synthroid for about 8 years, and found it was giving me severe pain in my hip. My doctor was uninterested and said this was impossible, so I found another doctor who listened (even though he didn't believe me either) and he switched me to Eltroxin. This made no difference, but at least this doc sent me for physiotherapy, which helps a lot. Now I am getting bad pains in my shoulder, which go away when I stop taking the Eltroxin for a few days. Anybody have similar experiences? Anybody find a solution to this kind of problem? Thanks to all.