Connection between T3 and Oestrogen dominance - Thyroid UK

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Connection between T3 and Oestrogen dominance


I was hoping to get some advice from this amazing forum:

I am now exclusively on T3 at 60mcg per day on the advice of my endo and psychiatrist after stopping NDT on which I felt much better in myself, however I had to keep raising the NDT doses to maintain my T3 on the upper end of the range on which I feel much better. I confess I don' think being on exclusive has resolved my problems as I still feel very lethargic. Whilst my hair has now stopped falling out, I have also gained around 5kg since stopping NDT and moving to exclusive T3, which is upsetting me a great deal.

When my period was late, my endo tested my female hormones and found my oestrogen to be over 2000. This is way over the max of the mid cycle range which is circa 1200.

I have done some research since then and discovered that T3 meds can apparently lead to oestrogen dominance, which in turn causes water retention and weight gain, depression and anxiety and fatigue. So it's now the proverbial chicken and egg problem..

Aside from weight gain, I am even more concerned since my late mother passed away from secondary oestrogen dominant related breast cancer..

Any advice or wisdom very gratefully received.

12 Replies

Hi Sangrom,

I’d be interested to read that research can you please share a link.

I thought estrogen dominance caused thyroid resistance as it raises TBG.

Many thanks Missimal. Yes I have also read that estrogen dominance can be caused by thyroid resistance, which makes sense in my case as I have the DIOI gene..

However I did read in an article that T3 meds specifically can increase estrogen, however very frustratingly and despite much Google searching, I cannot find the article again..

However I did find this (which does make sense as I have definitely noticed that I have decidedly more painful breasts since being exclusively on T3..

Thanks for sharing

I’m having problems with estrogen clearance due to a COMT gene so will mention this to my endo

How interesting Missimal- I have COMT gene too..

I am starting to wonder whether oestrogen dominance was always a problem with my symptoms and that increasing the T3 affected things further..

It's all so complicated it makes my head swim..

I'm on T3 only and the highest my oestrogen has ever been is 265 (but I am post menopause on HRT)

Thanks Angel_of_the_North- I think my values were taken mid-cycle and the level is still far too much..

Curious, would this possibly just be more of a problem for women in child bearing years rather than menopausal?

I know that T4 raises SHBG, which can lower testosterone. I wonder if T3 does the same.

If this is helpful, I have managed to reduce water retention and PMS horrors by using progesterone cream, agnus castus, DIM and calcium D Glucarate. Also been using seed cycling - just google - very easy. I had no sign my period was due this month, when usually I would be constipated and painfully bloated for half the month.

Sangrom in reply to Katedg

Thank you so much Kate! I shall definitely try what you have advised. I have been trying Agnus Castus- what dose do you take? And how much progesterone cream do you use?

Thanks again for taking the time to respond

Katedg in reply to Sangrom

I take a 'one a day' capsule - lots of those available online. Best to look up possible doses from herbalists. Personally I use half a teaspoon of Serenity every day because my oestrogen dominance was severe, but that is a trial and error process until you get to the point where your symptoms improve.

Thank you so much Kate- really helpful!

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