My mother had thyroid since 10 years and from that period she has been eating 100 mcg thyroxine but I'm worried that if it will have bad effect on body. Within few days again thyroid test was done, and report of thyroid test are as follows TT3- 0.87,TT4-7.23,TSH-1.12. Hence, I wanted to that what value of thyroxine she should take. Her body weight is 56 kg. Height - 146 cm.