Nausea? Is this common: Hi all, wondered if... - Thyroid UK

Thyroid UK
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Nausea? Is this common


Hi all, wondered if anyone knows if levothyroxin can make you nauseated? I started taking them approx 8weeks ago, on the lowest dose 25mg as my normal TSH is around 4 (within normal range) but they need it under 2.5 for fertility reasons. I’ve been feeling extremely nauseous for the last two-three weeks now but apparently, according to my fertility doctor it wouldn’t be down to the levothyroxin.

Anyone else suffer the same? Heard of this?

11 Replies

It could easily be down to the levothyroxine.

There are four (?) different brands of Levo that can be dispensed by pharmacists in the UK. If you don't get on with one of them, then make sure you get a paper prescription given to you that you can take where you like. Phone up different pharmacists in your area, tell them what your prescription and dose is, and ask what makes of Levo they have available. If they only have the one you are currently using, try a different pharmacist.

For info on the different brands/makes/trade names, see this link :

Note that it is common for people to have adverse reactions to the inactive ingredients in a pill, rather than the active ingredient.

in reply to humanbean

Thank you very much! I will ask the necessary! Glad it’s not me going crazy!

Most, or perhaps even all ingested drugs have the capacity to make us feel nauseous, it's one of the most common reported side effects although it can be for different reasons - some meds act on the part of the brain that controls nausea and vomiting, some irritate the stomach lining, sometimes there's a digestion problem, some meds stay in the gut longer, causing irritation, sometimes drug interactions can cause nausea if you are taking more than one, and sometimes the inactive ingredients in a tablet, the excipients, can cause nausea. It can be short term and temporary, or some times some people continue to experience that side effect. On the balance of probabilities, it's likely not to be the levothyroxine itself, but you may have an intolerance to one or other of the excipients. There is lactose in most Levo brands, and whilst an exception is Teva which is lactose-free, Teva has acacia, which some may be intolerant of, for instance.

Thank you MaisieGrey! Much appreciated!

I just found it odd that it seems to be mornings and evenings mainly. I also seem to be constantly hungry but maybe that’s just too many mince pies at Xmas☺️ Thanks again

in reply to DeeEndo

Which brand of Levothyroxine are you currently taking?

Many patients do NOT get on well with Teva brand of Levothyroxine. Though it is the only one for lactose intolerant patients

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.

25mcg is only half the recommended starter dose.

Levothyroxine doesn't top up your own thyroid hormone levels, it tends to turn your own hormone production off because it lowers TSH

Many medics don't seem to understand this

We need to start on 50mcg and bloods retested 6-8 weeks after each dose increase.

Dose is increased slowly in 25mcg steps until TSH is around one and FT4 at least half way in range

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. 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)

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

Obviously good vitamin levels are essential if TTC


As you have endometriosis you need both TPO and TG thyroid antibodies tested to see if you have autoimmune thyroid disease (also called Hashimoto's)

Hashimoto's and endometriosis can be linked

in reply to SlowDragon

Thanks slow dragon, I’ve had all of the above tested and all ok.

in reply to DeeEndo

vitamin D should be over 75nmol

B12 and folate above half way in range

Ferritin over half way in range

TPO and TG antibodies below top of range

Can be worth having an ultrasound of thyroid too

I got very nauseated on generic brands of Levo due to the filler ingredients. You can ask your druggist for a different brand and see if it makes a difference.

in reply to milkwoman

All UK levothyroxine is, technically, generic. But all UK levothyroxine is also one of four "brands" in terms of manufacture and licencing - though one is also packaged for teo specific pharmacy chains.

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