Hi JD, I was diagnosed with an underactive thyrood in the early 1990s, I had no idea why i was so down and lethargic and ached all over, after 6 months on the thyroxin i was buzzing again, it is a strange thing, it affects so much, but there is no worry once you get established on the tablets, but if you are inconsistant taking them, it will tell, in weight gain, mood swings, emotional outbursts, food fads, food allergies, shopping sprees, random arguments, did i mention chocolate binges and random mood swings? well did I? answer me for fruck sake!!!!!!!!!!!!!!!!!