My doctor changes my dosage on my thryoid med every 3 months. i have hypothyroidism. i go from 112 mg to 100 back to 112, etc. why?

Refining supplement: The main effort in treating hypothyroidism is trying to match what your body would make/need naturally if your gland had not developed the problem. The effort is guided by a blood test that looks at signals sent out by your brain saying your thyroid level is low, okay or high. It is with that level you doc may increase or decrease dosing.