Thyroid UK

Switching from Nature Throid to Armour

I have been on 2 grains of nature thyroid but have trouble sleeping and distended abdomen. If I go up to 2 1/4,grain I get ringing in my head and ears. So I started on 2 grains of Armour and want to know how long before it will get in my system. I'm on my 4th day and am sleeping better, but very tired, but my digestive tract seems to be moving better, ringing is off and on. Is 2grain Armour the same as 2 grain Nature Throid?

5 Replies


The active ingredients 38mcg T4 and 9mcg T3 in 1 grain are the same. This link lists the ingredients


2 grains of any NDT should be roughly equivalent. 1 grain is around 100mcg of levo (although some think the effect is about 75mcg). I found Nature throid about 100mcg equivalence.


Most NDTs have the same active ingredients and ratios. Erfa is the exception. What varies between the different brands are the fillers and the way the active ingredients is loaded in to the body (can't remember the technical term) -this is what a pharmacist once told me.

You may get different efficacy from different brands depending on how sensitive you are to the fillers in the tablets or the uptake method used by that particular brand.

All in all it is fine to switch directly across without reducing the new meds dose, although some people choose to do this there is no need to do so.

Hope the new brand works better for you. I found a big difference in how well I felt depending on the brand used. Most of us find the NDT brand that works best for us and stick to it for that reason.


I found Slow Release NDT was much better for my stomach. I would feel like I had an acid stomach and mild headache for 2-3 hours after taking 1 grain of NDT. The stomach thing would compound over days - slowly getting worse until I would go off NDT for a few days.

Re Sleep - I really struggle when I'm slightly hyper on NDT and on any amount of T3. The best thing I found for sleep is Androforte 5 (testosterone 2 x .5ml perday) . Warning the first few nights you are worse and then you'll love i, also you will have a bad time when you stop taking too.

When you find a solution for tinnitus let me know. Mine gets worse the more T4/NDT I take.

1 like

This bit about the tinnitus is very useful. Thanks.

I've been taking levo for nearly 30 years. A few months ago I started getting yo yo test results, not to mention feeling rubbish. The tinnitus is new too and drives me batty. My doctor told me I was hyperthyroid (first time in my life after being on same dose!) and to reduce the amount I was taking. Finally, again at my doctor's suggestion, I stopped Eltroxin LF for a week (I'm allergic to maize). The ringing in my ears lessened as each day past and I started feeling and sleeping better. Then I started again on Tirosint. As it kicked in the ringing came back. It appears to be a sign of toxicity, intolerance or allergy. At least in my case. Thinking of switching to NDT. Unfortunately, it's illegal where I live. :-(


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