High antibodies on Levothyroxine: I had a thought... - Thyroid UK

Thyroid UK

115,790 members134,300 posts

High antibodies on Levothyroxine


I had a thought and wonder if someone could clarify.

My antibodies are 402 which is high and I am unable to take Levothyroxine except in a low small dose every 2nd day (I now take T3). I am wondering would the antibodies be having an affect on what's happening re my inability to tolerate T4 or is this a straight T4 to T3 conversion problem?

3 Replies

A conversion problem exists when T4 isn't being adequately converted to T3, so nothing to do with you feeling unable to take T4 at the required daily dose. You would only know that by comparing your FreeT4 and FT3 results from the same blood draw, when unmedicated or taking Levothyroxine; once taking T3 you can't make the same assumptions. It's unlikely that having autoimmune Hashimoto's is affecting your intolerance of T4, that is much more likely to be sensitivity to one of the inert ingredients - have you tried different makes? What symptoms do you experience when trying to raise your T4?

saniagi in reply to MaisieGray

I have tried all brands of T4, with poor result. I get rashes, itchy skin, joint pains to the severity that I can hardly get out of bed. When I stop taking it these symptoms go away. I started T3 and felt I had my life back.


High antibodies confirms that cause of your hypothyroidism is due to autoimmune thyroid disease also called Hashimoto's

For full Thyroid evaluation you need TSH, FT4, FT3 plus TPO and TG thyroid antibodies and also very important to test vitamin D, folate, ferritin and B12

Private tests are available. Thousands on here forced to do this as NHS often refuses to test FT3 or antibodies or vitamins


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 special offers, Medichecks usually have offers on Thursdays, Blue Horizon its more random

All thyroid blood tests should ideally be done as early as possible in morning and fasting. Do not take Levothyroxine dose in the 24 hours prior to test, delay and take immediately after blood draw. This gives highest TSH, lowest FT4 and most consistent results. (Patient to patient tip, best not mentioned to GP or phlebotomist)

If also on T3, make sure to take last dose exactly 12 hours prior to test

If antibodies are high this is Hashimoto's, (also known by medics here in UK more commonly as autoimmune thyroid disease).

About 90% of all hypothyroidism in Uk is due to Hashimoto's. Low vitamins are especially common with Hashimoto's. Food intolerances are very common too, especially gluten.

Link about thyroid blood tests


Link about antibodies and Hashimoto's



List of hypothyroid symptoms


NICE guidelines saying how to initiate and increase. Note that most patients eventually need somewhere between 100mcg and 200mcg Levothyroxine


Ask GP for coeliac blood test and vitamin tests ASAP

According to Izabella Wentz the Thyroid Pharmacist approx 5% with Hashimoto's are coeliac, but over 80% find gluten free diet helps, sometimes significantly. Either due to direct gluten intolerance (no test available) or due to leaky gut and gluten causing molecular mimicry (see Amy Myers link)

Changing to a strictly gluten free diet may help reduce symptoms, help gut heal and slowly lower TPO antibodies







As MaisieGray says ......trying different brands of Levothyroxine

Many people can't tolerate Teva Levothyroxine

Always take Levo or T3 on empty stomach and then nothing apart from water for at least an hour after. Many take early morning, on waking, but it may be more convenient and possibly more effective taken at bedtime.


Other medication at least 2 hours away, some like HRT, iron, calcium, vitamin D or magnesium at least four hours away from Levothyroxine

Many people find Levothyroxine brands are not interchangeable.

Once you find a brand that suits you, best to make sure to only get that one at each prescription. Watch out for brand change when dose is increased or at repeat prescription. Many patients do NOT get on well with Teva brand of Levothyroxine. Though it is the only one for lactose intolerant patients

Come back with new post once you have results and ranges on all tests

You may also like...