I have recently reduced my dose of Armour from 2.75 grains to 2.5 grains, as I was feeling slightly over medicated. I have been on 2.5 grains for a week or so and have been experiencing a rapid pulse for the last couple of days. This morning after my first dose of 1 grain my pulse was 105 bpm and I felt a bit weird. I haven't taken my 11am dose and don't think I will take any more today. My pulse is now 85 and I feel ok, although I'm having some palpitations. I can't understand why 2.5 grains would suddenly be too much for me I think my iron is Ok - I'm still taking ferrous fumerate and thx last test showed ferritin of 98. I am not feeling particularly hypo or hyper at the moment and wish I understood what is going on.