Side Effects of Levothyroxine: Hi, I have not... - Thyroid UK

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Side Effects of Levothyroxine

Hash21 profile image


I have not been taking Levothyroxine for long (approx 3 months). This post isn't about my blood tests etc. but more about the medication Levothyroxine. The original reason for seeing a GP was because of bone/leg/muscle pain and aches which have improved since taking the medication as I was diagnosed with Hashimoto's as a result of the blood tests taken.

However, my question relates to what I feel are side effects of the medication as before starting to take it I didn't seem to suffer from any of the following but now (having taken Levo for 3 months) I am exhausted, completely demotivated and feel low, I feel boiling one minute and freezing the next. My eyesight has also deteriorated both short and long distance so it would appear to get eyes tested too.

I don't understand why I wouldn't have felt this before taking medication and feels like it has come on since starting. Is this right? it is tempting to not take the medication so that I can feel better but then I guess other symptoms will return. Very frustrating.

6 Replies

Hi. What brand of levo are you taking? Many people have awful side effects with Teva.

Hash21 profile image
Hash21 in reply to LMor

ALMUS. I am taking 50mcg daily.

SlowDragon profile image
SlowDragonAdministrator in reply to Hash21

Bloods should be retested 6-8 weeks after each dose increase

50mcg is only a starter dose

The aim of Levothyroxine is to increase the dose slowly in 25mcg steps upwards until TSH is under 2 (many need TSH under one) and FT4 in top third of range and FT3 at least half way in range

Extremely common to have low vitamin levels when hypothyroid, especially if cause of your hypothyroidism is due to autoimmune thyroid disease also called Hashimoto's diagnosed by high thyroid antibodies

Have you had vitamin levels and antibodies tested?

Add thyroid and vitamin results and ranges if you have them

For full Thyroid evaluation you need TSH, FT4 and FT3 plus both TPO and TG thyroid antibodies tested. Also extremely important to test vitamin D, folate, ferritin and B12

Low vitamin levels are extremely common, especially if Thyroid antibodies are raised

Recommended on here that all thyroid blood tests should ideally be done as early as possible in morning and fasting. This gives highest TSH, lowest FT4 and most consistent results. (Patient to patient tip, best not mentioned to GP or phlebotomist)

Last Levothyroxine dose should be 24 hours prior to test, (taking delayed dose immediately after blood draw).

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

Medichecks currently have an offer on until end of May - 20% off

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.

If not had bloods retested get them done asap

Dose of Levothyroxine likely needs to be increased to 75mcg and bloods retested 6-8 weeks later

NHS guidelines on Levothyroxine including that most patients eventually need somewhere between 100mcg and 200mcg Levothyroxine.

Also what foods to avoid (note recommended to avoid calcium rich foods at least four hours away from Levo)

Always take Levo on empty stomach and then nothing apart from water for at least an hour after.

Many take Levothyroxine 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

wagnermia profile image
wagnermia in reply to SlowDragon

I copy/paste many of your posts (plus a few other folks on this great forum) and save them in a ‘thyroid notes’ file... just FYI, letting you know how much everyone’s time, knowledge etc is appreciated! M.

It could be the medication itself; however after 3 months time, ask your gp to take labs for comparison against the originals taken before you started the med. (I feel much worse when UNDER medicated than when NOT medicated. This was a big stumbling block that kept me in ‘medication limbo hell’ for far too long) But before you can really explore what’s going on, the blood work is where to start. M.

I had bad side effects taking Levo ... change the brand

Hope you are ok soon 😊

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