Hashimoto's disease
"I am a 29 year old female.  I was diagnosed with thyroid cancer when I was 24.  My entire thyroid was removed, and I have been on levothyroxine ever since (about 4 and a half years now).  The medicine works great for the most part, I wouldn&#039;t be able to move or have energy for anything if I wasn&#039;t on it.  I take 150mg per day.  Considering that I&#039;m young, I started researching for long term effects.  There do not seem to be any extreme, significant, effects which is great.  "