Thyroid UK

advice on levothyroxine dose


I joined this forum a week or so ago and have found out more about hypothyroidism in that week than I have in 6 months toing and froing from my GP! My last visit was the most reassuring so at least I now know which GP to ask for infuser. Anyhow, I was diagnosed with hypothyroidism in July last year and started on 25mg of levothyroxine in September 2016. Dose was upped to 50mg 6 weeks later but I soon started having severe heart palpitations. Went back to GP who advised me to reduce my dose of levo to alternate daily between 25 and 50mg. Palpitations settled down but hypo symptoms are now returning. I have chronic anaemia and struggle to tolerate iron so it has been a constant battle to raise my iron levels at all let alone get them in range (being a veggie doesn't help). Had heart trace done in the past that showed a leaky mitral heart valve. Palpitations were put down to iron deficiency. Had a recent HBO count done, waiting on results for that and latest thyroid test results. Has anyone else had these side effects when starting levo? Any advice would be really appreciated as I'd like to go back to my GP fully armed!

It's probably worth noting I am also deficient in B12 and Vitamin D and take meds for both.

7 Replies

Do you know if you have had thyroid antibodies checked? There are two sorts TPO Ab and TG Ab. (Thyroid peroxidase and thyroglobulin) Both need checking, if either, or both are high this means autoimmune thyroid - called Hashimoto's the most common cause in UK of being hypo.

NHS rarely checks TPO and almost never checks TG, seeming to think it is impossible to have negative TPO and raised TG. It's rare, but not impossible, there are a few members on here that have this.

If you have Hashimoto's (high antibodies) then you may find adopting 100% gluten free diet can really help reduce symptoms, and lower antibodies too. Selenium supplements can help improve conversion of T4 to T3

ALWAYS Make sure you get the actual figures from tests (including ranges - figures in brackets) for all tests. You are entitled to copies of your own results.

vitamin d, b12, folate and ferratin all need to at good (not just average) levels for thyroid hormones (our own or replacement ones) to work in our cells. When on B12 injections or supplements, usually recommended we also take B complex as well to keep all the B's in balance.

How much vitamin D and what brand are you taking. Recommended we also take magnesium and Vitamin K2 when taking D. Magnesium is recommended for the vitamin D to work (might also reduce/stop palpitations). When on high dose vitamin D, this increases the calcium going around and Vitamin K2 helps send calcium to bones rather than fur up arteries


Thank you for your reply slow dragon. I'll hopefully obtain my results tomorrow when I go for b12 injection.(receptionist wouldn't give them to me without asking the doctor first). I was tested for celiac but that was clear. Does this mean gluten won't affect my thyroid or is it a separate issue? Vitamin D supplement is HuxD3 20,000IU(vitamin D3 500mcg). I started with 2 for 10 days followed by one a week. I was told I would have to buy my own after this if levels are still low. I know you can't recommend specific supplements but could you point me in the right direction with regard to magnesium, K2 and Complex dosage/source? There's so much contradicting information out there, it's a mine field!


Many of us buy on-line - more choice and often cheaper

B complex - look for one that includes folate rather than cheaper folic acid. B complex often recommended are Jarrows or Thornes. These are quite high dose. Some people find them too high. Can cause niacin flush. Take any B complex in morning with breakfast as can be quite stimulating.

Magnesium - masses of different ones. Do a search on here for lots of different recommendations.

K2 should apparently be Mk7 rather than Mk4.

Also selenium supplements.

Loads of us are gluten intolerant, but not classed as coeliac.

Vitamin C helps too

Read Chris Kresser

Dr Datis Kharrazian

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thanks for that slow dragon. I'll write my shopping list!

Results from bloods taken in December (as others have experienced with GP testing not the most extensive of tests !)

Serum TSH level 3.74 mu/L (0.35 - 5.00)

Serum free T4 level 14pmol/L (9-19)

GP won't give me HB results as he wants to see me first.

I would appreciate some feedback on the above results and advice on whether I should ask GP for more extensive test or get it done privately.


You need both types antibodies tested - You can see if GP

If not go private

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Some people do get palpitations when on levothyroxine. For some it is due to too low a dose also.

A low dose can give us palpitations as our heart needs thyroid hormones to work efficiently as does the rest of our body.

Do you take supplements well apart from levothyroxine.

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Thank you for your reply Shaws. The palpitations started after the GP increased the dose from 25 to 50mg. I now alternate 25 and 50mg daily, this seemed to settle the palpitations but symptoms of hypo definitely returning :-/ I don't tolerate iron well, I have IBS and iron often triggers it. I've tried various alternatives such as spatone iron drink and vitabiotics feroglobin. They are fine but hardly make a dent on my iron levels. The strength is a lot less than GP prescribed iron.


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