My son aged 18 weight 49 was diagnosed with hyperthyroidism (Grave’s disease). Very high T3,T4 and FT4 ,TSH<0.01,TSHR-Ab : 20, AMA:146. He was put on NeoMercazole  (20mg) one time daily and continuing it for last 8 months. Now his T3(85)/T4(5.7)/FT4(1.03) are in normal range but TSH is still <0.01 and AMA:33. Weight increased to 56. To normalize TSH , the doctor advised to increase the dose to 30mg/day. We are confused whether to increase or decrease or continue with the same dose….our worry is T3/T4/FT4 might go below normal range and he might become hypo. Any suggestions are welcome.