Increase in thyroxine: Further to my last 2 posts... - Thyroid UK

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Increase in thyroxine


Further to my last 2 posts, (I have a low TSH and T4 has been slowly dropping)

I went to see my sympathetic GP who agreed to trial an increase from 75mcg (the dose I have taken for 15 years) to 100mcg for a month... and then review.

He is also referring me to an endocrinologist (which may involve a long wait)

I have now taken the increase since Monday and I’m worried I am overdosing!

My exercise intolerance is even worse (shortness of breath and rapid heartbeat)

I have loose stool and I’m sweating.

On the plus side, I’m not as boiling at night and the daily morning pressure headache has gone.

My question is: does it take a while for the body to adjust to the dose change?

My symptoms were not typical of hypothyroid but a mixture of both hypo and hyper which I read is possible if the problem originates from The pituitary gland (which: due to my low TSH for the last 15 years, I think it may be)

I am also on B12 injections, I read that B12 deficiency can go hand in hand with this.

Has anyone any thoughts? I will persevere with the increase, I have to report back to the GP in a month...

Thank you 😊

10 Replies

I find increases in Levo of 25mcg at a go too much for me and my heart is very sensitive to any increase - maybe you need to increase more gently? Perhaps alternate 75 and 100? Or try 2 or 3 x 100 and the rest 75 so you can space the 100s out more? When on an increase I literally introduce 1 extra dose per week for 4 weeks then another (if that make sense), it means increasing dose is slow, but it means my heart has time to adjust. 🤸🏿‍♀️🥛


Have you had change in brand of Levothyroxine when dose was increased to 100mcg?

Many people find different brands are not interchangeable. Teva brand especially upsets many people

As suggested in previous posts, it's essential to test vitamin D, folate and ferritin

You already have low B12. Other vitamins may be low too, they need to be optimal for thyroid hormones to work well

Ask GP to test ferritin, vitamin D and folate now

Low iron or low ferritin can cause breathlessness

Ideally waiting 6 weeks minimum to test thyroid levels after any dose change

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

Is this how you do your tests?

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

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. So it's important to get TPO and TG thyroid antibodies tested at least once .

Link about thyroid blood tests

Link about antibodies and Hashimoto's

List of hypothyroid symptoms

Vitamin D test

Hi, I take B complex, mineral support solution , Vit D 1000 iu, folic acid. My herbal medicine has got in it...

Comfrey root, marshmallow root, calendula, chamomile, skullcap, wild oats, Californian poppy, valerian, feverfew, wood betony, cleavers, nettle root, golden rod, black elderflower root, wild indigo and echinacea

I tried to send pics but can’t work out how to attach!

I have been seeing my herbalist for over 4 years, he tells me when I need medical consultation, he told me about the B12 and keeps telling me about my under-active thyroid

SlowDragonAdministrator in reply to Countrylou

Does your mineral solution contain iodine? Iodine is NOT recommended for anyone with Hashimoto's



I tried to send pics but can’t work out how to attach!

You can add one photo to the opening post of your thread. See:

You will see "Add a Photo" below the main message box, click on it and follow instructions to upload your photo.

Have you checked for interactions with Levo for all the ingredients of your herbal medicine?

My symptoms were not typical of hypothyroid but a mixture of both hypo and hyper which I read is possible if the problem originates from The pituitary gland (which: due to my low TSH for the last 15 years, I think it may be)

That is typical of autoimmune thyroid disease, aka Hashimoto's. You need to test Thyroid Peroxidase and Thyroglobulin antibodies.

Countrylou, I find almost anything can happen in the first few days and weeks on a new dose. The body definitely needs time to adapt. If you're exercising I would probably rest or stick to something very gentle, be kind to yourself.

I always try to stick it out for 6 weeks and have a blood test even if symptoms seen strange, and only stop if they become unbearable.

I've just clicked through to have a look at your thyroid panel. You were very undermedicated, so I very much doubt you're overmedicated now. Your freeT3 was in the bottom third, and probably you'll need it in the top third to be well. FreeT4 almost certainly needs to get all the way to the top.

Just hang in there, and hopefully you'll feel improved in a few weeks time.

PS: If I were you I'd try to extend the period and see your GP to evaluate in 6 weeks rather than 4. Its best practice to wait 6 weeks before having blood tests, and personally I find about 3-4 weeks can be the worst time for weird symptoms. Waiting the full length of time may mean you get a better evaluation of the new dose to show the doctor.

Thank you so much for this, I must admit I was panicking especially as I felt so ill yesterday afternoon I had to go to bed. I feel fine again today and am concentrating on the fact that my body temperature is constant at night now instead of unbearably hot and I haven’t had a morning pressure headache for 3 days 👍🏻

(I’ve had them daily since January)I will go and see GP again in about 6 weeks ... I can just take extra of my existing 25’s and 50’s to make it last that bit longer.

I am usually very active but since the increase I haven’t walked as much.... not felt up to it

If I were you I'd go easy on being active and rest as if you had a flu or something, and take good care of yourself with your feet up :) Your body is adjusting all its chemistry to make use of the new hormone it has, I think it can be a bit of a shock to the system.

Good to hear you are already getting some benefits! In a few weeks it should smooth out and hopefully the more negative things will calm down.

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