LOW TSH: I am a new member - I had no idea this... - Thyroid UK

Thyroid UK

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I am a new member - I had no idea this oganisation existed but desperation led me to search the 'net and thankfully I found it.

I have had auto-immune hypothyroid disease for 30 years and never felt well and 'me' until I was given T3. My consultant said my body was not converting T4 to T3 - how would she know this ?

My GP stopped the T3 some years ago as I was having arythmia and palpitations - these did not stop and it was clearly not the T3 causing these symptoms which eventually stopped when I stopped another medication. My Dr refused to give me T3 again. I had little energy etc but coped, with my husband doing most of the work etc.

Now my consultant has reduced my T4 to 100 from 150 because my TSH was very low, T4 normal, T3 also low. I felt as bad if not worse than I did before I was diagnosed - unable to get out of bed - couldn't add 2 and 2, all the symptoms of undiagnosed hypothyroidism, so I have put myself back on 150 levothyroxine for now.

I do not feel over medicated on 150 so I was wondering whether other medications or anything else could be suppressing my TSH levels . I also have Addison's Disease and take T4 and 3 different steroids, hyrocortisone, fludrocorisone and DHEA, altogether first thing in the morning. My blood tests are always taken within a couple of hours of taking meds, hoping someone may have some answers as life is simply not worth living if I am forced to continue on 100 mcg per day

8 Replies

Padco, your endo determined you weren't converting well because your TSH will have been low with high (in range) FT4 and low FT3.

Other medication can reduce absorption and uptake of Levothyroxine. For maximum absorption Levothyroxine should be taken with water on an empty stomach ie 1 hour before or 2 hours after food and drink, 2 hours away from other medication and supplements, and 4 hours away from iron, calcium, vitamin D and oestrogen.

Taking Levothyroxine before a blood test skews results. In future leave 24 hours between last dose and blood test which should be early in the morning when TSH is highest, and fasting (water only) as TSH drops post-prandially. Take Levothyroxine after the blood draw.


I am not a medical professional and this information is not intended to be a substitute for medical guidance from your own doctor. Please check with your personal physician before applying any of these suggestions.

patdo in reply to Clutter

Thank you

Hi pat, It's quite difficult when both your adrenals AND your thyroid are not in working order. Having a non existent TSH when on treatment hormone is quite normal. Your pituitary recognizes your outside hormone, but T4 needs to become free T3 to be available to your cells. Your cortisol levels have to be adequate as well as iron for conversion and with your situation, I wonder how accurately you can do that. This makes taking T3 almost mandatory, doesn't it? I think it was reckless to take away your T3 under these circumstances and even worse to lower your levo. And actually, the FT3 value in most cases determines whether you are over medicated or not. Your levo is a T4 hormone and does very little until it is converted to FT3 which you say is LOW. So of course you are not well. If you only have these foolishly reasoning doctors overseeing your problems, I advise you to order your own T3 and add sufficient to bring up to your former levels that make you feel well.

I also now wonder if they are making obvious errors treating your Addisons as well.

This was posted recently.


patdo in reply to Heloise

Thank you Heloise - is T3 easily available?

Heloise in reply to patdo

If you are in the UK (I'm in the U.S.), it seems there are several options. Ask for private messages regarding it. I think the same for natural desiccated if you want to drop Levo entirely.


Get on WP thyroid. Avoid polyunsaturated fats. Get plenty of sodium. Read this


You could have a look at my posts on the forum. I have been on a journey of discovery with a low TSH, low T3 and good T4 levels.

I hope you get some answers :)


Can you add your blood test results from when on 150mcg

TSH, FT4 and FT3 if you have them

Medics have ridiculous obsession about low TSH, but when on Thyroid replacement hormone a TSH is largely irrelevant. As long as FT4 and FT3 are within range you are not over medicated. FT4 should be near top of range and FT3 at least half way in range.

Low vitamins are very common, especially if you have high thyroid antibodies. Do you know if these were ever tested? This gives diagnosis of autoimmune thyroid disease also called Hashimoto's

Likely to be high as 90% of hypothyroidism is due to autoimmune issues. Also with Addison's I guess this is autoimmune too

For full evaluation you ideally need TSH, FT4, FT3, TT4, TPO and TG antibodies, plus vitamin D, folate, ferritin and B12 tested

See if you can get full thyroid and vitamin testing from GP. Unlikely to get FT3

Private tests are available


Medichecks Thyroid plus ultra vitamin or Blue Horizon Thyroid plus eleven are the most popular choice. DIY finger prick test or option to pay extra for private blood draw. Both companies often have money off offers.

All thyroid tests should be done as early as possible in morning and fasting and don't take Levo in the 24 hours prior to test, delay and take straight after. This gives highest TSH, lowest FT4 and most consistent results

Link about antibodies


Link about thyroid blood tests


Print this list of symptoms off, tick all that apply and take to GP


You need to be managed by a pro T3 endocrinologist with good knowledge of adrenals too

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