Based on how high or low the ... are normal, the pituitary gland stops producing TSH. The TSH test measures how much or how little TSH there is in the bloodstream. Thyroxine (T4) is one of two ...

Levothyroxine (L-T4 ... use a serum TSH target value of 0.05-0.1 mIU/L for low-risk patients and a TSH of <0.01 mIU/L for high-risk patients. Some physicians use a low-normal range therapeutic ...