HRT and absorbtion thyroid hormones

[AKatieD]

I found the section below on oestrogen and t4/t3 absorbtion on the TUK website.

I have been taking HRT for 4 months for postmenopausal OA, have done usual blood tests and upped my t3 dose back towards optimal levels free t3, but still feel not right.

The TUK piece suggests that tests might look like taking enough t3 but it is not being absorbed. But talks about doing more testing of TSH which is obvs pointless.

Any suggestions on getting t3 dose right on hrt if absorption can be a problem?

TUK excerpt:

"Oestrogen (in the contraceptive pill and HRT), provides more of the transport protein making the hormone inactive. Any oestrogen raises the levels although thyroid activity is unchanged. This could make your levels look within the normal range, whereas they are really below it. After starting on any oestrogen therapy, a woman should always have TSH tested to see if the oestrogen is having an impact on overall TSH and thyroid function and may require a dosage adjustment"

[radd]

AKatieD,

Are you taking HRT orally, patches or gel?

The oestrogen in oral HRT can cause the liver to produce high levels of hormone protein transporters that risk binding too much thyroid hormone. This decreases the amount of 'free' that can be assimilated into and utilised by the cells.

Theoretically there should far less chance of this happening with patches or gel that bypass the liver but I have read about recycled oestrogen causing problems if there are excretion issues. I have now discontinued HRT but when previously taking body-identical oral progesterone & oestrogen gel, I never experienced any problems.

You will know if this is happening by testing your 'frees', (FT4 & FT3) as opposed to 'totals' (T4 & T3). For further investigation you could also test TBG and/or SHBG protein transporters.