Thyroid UK
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Researching T3 only vs NDT

Hello everyone.

As per the title I'm interested in hearing about people who have been on NDT or levo and swapped to T3 only.

After reading about food_ie's experience with T3 only I'm really interested to hear from anyone else who may have had similar experiences or even people who have tried T3 only and found that they had to go back to levo or NDT.

I don't plan to jump ship from NDT yet but I may try T3 only in the future.

6 Replies


I haven't medicated T3-alone and it suits some who can't tolerate T4 or NDT.

However, be aware it can be problematic for men as high levels of T3 can raise estradiol, which will not only increase thyroid binding globulin (TBG), which may stop T3 from being free (so unable to enter the cells) but also decreases androgens (male hormones).

You may want to read "The CT3M Handbook " by Paul Robinson to be aware of the pit falls.

Re previous posts: what do you mean by absorption issues ? If you are not absorbing, do you have trouble with iron and nutrients too ? ? ..

I think you just raised too much too quick, maybe creating too much RT3 ? ? ....thyroid receptor resistance ? ? ... . (When there is too much in the blood stream but it can't enter the cell) but without identifying your cause for feeling rubbish, you may experience the same on T3-alone.

A (possible) low iron level may be as problematic for T3-alone as it may be for NDT ! ! ... ;o))) ..


Thanks for the reply radd.

I think it's probably true I raised NDT too quickly. I've gained so much weight because of the hypo and I just didn't want to sit around too long on a low dose gaining more weight, I should have been more patient but it's really frustrating being well over the weight I was before things started to go wrong with my thyroid and nothing I try works in the slightest little bit.

I'm dropping a grain (NDT) as of yesterday to see if it reduces the sweating. Also as of yesterday I started adding 200mg of iron per day and I've ordered some vit d3.

So I guess it's not really a good idea for men to go on T3 only? I did plan on trying to get things right on NDT first anyway, I haven't given it enough time imo.

The absoption thing I was talking about was the fact that at really high doses of levo I was still not at the top of ranges for FT3 & FT4 so I assumed I had problems absobing levo properly, maybe the high dose of levo had caused RT3.



I think you still absorb (unless you have gut issues) but you don't utilise, so then have a load of thyroid hormone sloshing around in the blood stream unused. This will be a prime candidate for RT3 which may stop further from working ! ! ...

Men can medicate T3-alone as Paul Robinson has but I read it to be slightly more tricky.


Is there any chance that any RT3 I may have will reduce over time once I'm on the correct dose of NDT? I always take my NDT sublingual so that should be avoiding any gut problems I might have.

I doubt my GP will allow me to have RT3 tested, I doubt he will even know what RT3 is and I just can't afford to go private atm



Yes, I continually read of elevated RT3 naturally being eliminated by decay & excretion. Optimal nutrients & iron will help, and antioxidants, as it is the liver that has to do a lot of the clearing.

Milk thistle and dandelion leaf help... also selenium.


Milk Thistle & clearing RT3


Improving Thyroid Function


Thanks radd.

I'll have a good read of those :)


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