INITIALLY 50-100 MCG DAILY, BEFORE BREAKFAST, AND ADJUSTED AT 3-4 WEEKS INTERVALS BY 50 MCG UNTIL NORMAL METABOLISM IS STEADILY MAINTAINED, THIS MAY REQUIRE DOSES OF 150-300 MCG DAILY OVER 50 YEARS MAX. : 50 MCG ON ALTERNATE DAYS. FOR CRETINOUS INFANTS : INITIALLY 25 MCG DAILY INCREASING BY 25 MCG EVERY 2-4 WEEKS. JUVENILE MYXOEDEMA : 2.5 MCG/KG/DAY.