Hoobley - I ahve solved my problem of when to take thyroixine by taking it consistently ie always with breakfast. i probably take a little bit more, but much easier. If you need to take iron tablets, they really interfere w absorbtion of thyroxine and thyroid extract, so take them 4 hours apart (you don't have to worry about the iron in multivitamins, so little eg 5mg, doesn't make any difference). I finally got my ferritin levels up when my new endo recommended 100mg elemental iron each day.

MummaW - I haven't been taking thryoxine long enough to compare what happens. Why are they testing progesterone at D21, what are they looking for?