Thyroid UK

Blood results on erfa

Hi! What do you think of these blood results on erfa? I'm taking 60mg first thing and 45mg at 1pm. I feel very hypo still but have lots of other health issues going on, so I don't honestly know what causes what!

Tsh 0.21 (0.27-4.2)

Ft4 12.2 (12.0-22.0)

Ft3 4.7 (3.1-6.8)

My doc isn't keen on raising my dose any more because my tsh is low and I'm osteopenic.



8 Replies

Do I know you *wink*? On the face of it you look like you could manage an increase, don't you? TSH not suppressed and FT3 low in range? Agree with you that it can be quite difficult to figure out what is causing what when thyroid is only part of the picture.

I'm no help at all, am I?


Your FT3 and FT4 are still low, so I would think there's room for improvement. Remember, Erfa contains calcitonin which helps protect against osteoporosis (I think - look it up to be sure). I suspect the lack of calcitonin is why doctors don't like T3 therapy suppressing TSH, as the thyroid no longer produces any of the other hormones. But Erfa contains all of them.


To be honest, I think that you are more likely to see your osteopenia worsen if you can't get your levels of thyroid hormones up a little higher, especially if you are still experiencing symptoms.

Have you had your vitamin D checked recently? This is extremely important for good bone health as is magnesium. Vitamin B12 can also have a big impact. B12 should be above 400/500 depending on units used.

Incidentally, the only times low TSH causes osteoporosis and osteopenia (that I'm aware of) is when you are actually hyperthyroid or you are hypothyroid and your thyroid hormone replacement is causing your T3 to be high enough to cause hyper symptoms or is over the range. Perhaps suppression may have an effect in some cases.

I am not a doctor but I feel that your doctor is worrying unnecessarily and by not prescribing enough thyroid hormone could be putting you at greater risk of developing osteoporosis.

Recently Dr Midgley and his team have shown that the relationship between TSH and T4 is not at all as doctors currently believe if you are either euthyroid or hypothyroid but on thyroid hormone replacement. As you fit in the second category, your TSH isn't particularly helpful for determining whether you are on the correct dose of thyroid hormone replacement. Hopefully Dr Midgley's paper will be published in the not too distant future so that people like ourselves have some backup when visiting our GPs and those good GPs that want to help will have some evidence to present as to why they are treating according to symptoms rather than BTA guidelines.

Sorry I don't have any suggestions for convincing your GP. Some can be convinced and others can't :( All I can say is keep trying! I wish you well with it and hope that yours is one who can be convinced.

Carolyn x

1 like

Susie, I agree with Anstey and Rosetrees that there is room for a dose increase because your FT3 is low. The T3 in Erfa is probably why your FT4 is low in range as oral T3 bypasses the need for high levels of T4 to convert to T3.

I was diagnosed with mild osteopenia in June and have been told by endo to continue supplementing 5,000iu vitD3. I suspect severe vitD deficiency last year may be more responsible for my osteopenia than TSH which had been suppressed for 15 months and will continue to be suppressed for at least 4/5 years.

Excerpts from STTM and TiredThyroid about T3 suppressing TSH below. Your GP may take more notice if you include the research references rather than just printoff extracts from thyroid patient advocates.

...Patients who have switched to natural desiccated thyroid have discovered that when they are allowed to dose by the COMPLETE elimination of symptoms, which also puts the free T3 at the top of the range, they will end up with a TSH lab VERY BELOW range….and not one hint of hyperthyroid. It is not uncommon to see a TSH of .009 or .004 when optimal, for example, yet not one iota of hyper...

...And for further info, here’s the link to the webpage that states that “estimates of average normal secretion for euthyroid humans are 94-110 µg T4 and 10-22 µg T3 daily (259).” And that is approximately equivalent to 3-5 grains desiccated thyroid. And when you get close to or in that range of desiccated thyroid, you WILL have a suppressed TSH lab, which tells you how inaccurate the established man-made TSH range is.


...Any thyroid medication that contains T3, like Cytomel or desiccated thyroid, will suppress TSH levels. [7] One study (on rats) determined that the relative potency of T3 to T4, in terms of its ability to inhibit TSH, was 100:12. [8] The direct T3 in the blood is sensed by the hypothalamus/pituitary, the body determines that no additional thyroid is needed, so no TSH is released. A normal thyroid secretes only a minimal amount of T3. The majority of the body's T3 is converted from T4 as needed throughout the day, whereas someone on T3 or desiccated thyroid takes a concentrated dose of T3 all at once. This may explain the TSH suppression. Surprisingly, patients can have suppressed TSH levels on these meds but do not exhibit any hyperthyroid symptoms. Dosing by TSH will usually leave the patient undermedicated with hypothyroid symptoms.


Thank you very much everyone. Clutter, my vit d is fine now, but that's only a very recent thing, I have been very deficient until fairly recently when I found a vit d I could tolerate. Also, i breastfed my 2 children before knowing I was coeliac and vit d deficient, so I think that's why my bones are on the thing side (they are routinely checked due to my coeliac's). My vit d is about 70 now and my calcium is fine too.

I'm hopeful I can persuade my go to increase as I feel pretty rubbish and it looks to me like my ft3 could move up quite a bit yet.

Thanks again.


I too am on Erfa (having recently switched from Armour due to supply issues). I have been stable for the last year or so on 2.25 grains and am feeling very well :)

My results have consistently shown a suppressed TSH of <0.02 (so undetectable), low to mid range fT4 and fT3 above mid-range. My endo isn't delighted that my TSH is suppressed but has decided to accept it as my fT3 and fT4 are where he wants them. In order for my TSH to be in range, my t3 and t4 are below/bottom of the range and I feel dreadful.

I agree that an increase sounds like a good idea.


Thanks! My GP has agreed to an increase


Not sure what happened there, half my post didn't appear! I went on to say that with having an increase in my erfa and increasing my iron (I'm slightly anaemic), that I hope my energy levels will improve soon.


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