Does everyone on T4 only always build up reverse T3?

[YulianaRossenova]

So is it something like a prerequisite for people on T4 only to build up high levels of rT3 in the end?

I currently take 150 mcg levothyroxine and feel more and more hypo as each day passes by. I was fine on that dose in the beginning.

[diogenes Remembering]

Depends. If you are over-doing it, rT3 will act as a detoxifier. On adequate but not too much T4, the effect will be less. But there always will be something of a rise in rT3, if only because you have to take in more T4 to get the required FT3. Therefore in a sense the body is out of balance, compared with when you had a working thyroid.

[YulianaRossenova in reply to diogenes]

Can I be overdoing it even while I feel very hypo? Apparently I can.

Also I process T4 very quickly. I feel its effects right away, in a matter of 12 hours or so. I don't know why that is. Waiting for whole 6 weeks for the full effects of a dose to settle in has always done much more harm to me than good.

Is it possible that I felt good on 150 mcg T4 initially and now feel hypo because 150 mcg T4 is not enough to fully replace my thyroid production of hormones and instead slows down its function further by reducing TSH?

What if someone has a high rT3 and a high FT3 at the same time? And a good ratio of both? Doesn't high rT3 cease to be a problem in such a scenario?

Does conversion from T4 to rT3 slow down when TSH is near zero?

[startagaingirl in reply to YulianaRossenova]

Yes you can be overdoing it while feeling hypo if you don't covert well from T4 to T3. It is lack of T3 that makes you hypo, and drives TSH, not directly lack of T4. And too much T4 (as it is not being converted) does not reduce T3, only enough T3 will reduce TSH. And yes it is possible that 150mcg was enough initially but not now through at least 3 mechanisms:

1. your body opens up more receptors that had been dormant and sucks up the T3, hence turning up demand.

2. If you have Hashis your thyroid function could be declining and hence yu are producing less yourself.

3. Your nutrient levels are declining and hence your conversion rate is declining, you have less T3 per amount of T4 dose and you feel more hypo.

High RT3 and high FT3 is certainly possible - the body produces RT3 to either slow down the whole body in times of crisis or precisely because you have high FT3 in which case it acts as a protective agent against the potential damage caused to the system by high FT3. In this case - slightly simplified as actual process may be somewhat constrained - the high RT3 reduces demand for FT3 by blocking receptors, hence reducing demand for FT3, reducing TSH and hence reducing conversion from FT4.

I don't know which scenario applies to yourself without more info on free Ts, nutrients, etc.

Gillian xx

[diogenes Remembering in reply to YulianaRossenova]

1) too much T4 can actually not only raise rT3, but inhibit T3 production, so you may feel worse. 2) it may be possible to have both high FT3 and rT3, but only if you are badly overdosed AND are a good converter. It isn't the rT3 that's then the problem, its the FT3 excess. Remember also that all these numbers relate to your unique best positioning of the values - just talking about anywhere in the normal range does not help. So everyone has a "sweet spot" somewhere in the range suitable for them as an individual. This can be different in therapy from health. It just has to be found by trial and error.

[YulianaRossenova]

I am not a good converter.

I am trying to build up my levels of nutrients. It's only ferritin that is borderline low, but that is because I have a MTHFR mutation, my iron has always been very good, even without supplementation, as well as the rest of my iron panel (transferrin saturation is at 30% for example). I cannot take iron since it is 26 (10-30). Without supplementing.

I also have endometriosis which is known to lower ferritin levels through inflammation.

The other nutrient levels are getting better and better. I supplement with B12, D, folate, magnesium, zinc, selenium, etc..

I do have Hashi's!

It seems to me that I have another problem which few if almost no people have: I really process T4 very quickly, T3 as well.

If I skip a T4 dose, or if I take a lower one by any chance I can feel the effects on the next day. As if T4 for me is like T3 for others.

Same thing applies if I take a higher dose of T4. As if I am taking T3, not T4. I know it is weird and no doctor believes it but I have observed my reactions/response to T4 dosing very carefully over the course of more than a year now and I know that it has such a fast-acting effect on me.

I need a very high level of FT3 to function normally.

With reference ranges for FT3 3.95-7.80, I need at least 6-6.50 to feel normal, and my FT3 cannot go over 5.50, no matter how much T4 I take. It goes to 6 but only for a week after a T4 dose increase and then slumps down to 5ish.

I don't know why. FT4 is above range already. However I have read of people on 200-300-400 mcg T4 only, with FT4s TWICE the upper range and FT3s around 7-8 and these people feel OK.

Pure T3 does not seem to help, since I can feel its effects wane too quickly. I practically have to take more than 5 T3 doses a day to achieve something little...

When I add a small dose T3 (not more than 15 mcg for the whole day) to T4, I become even more hypo. I guess that has to do with the suppressing effect T3 has on TSH which in turn suppresses the thyroid T4 output and slows down T4/T3 conversion.

I really don't know what to do...

Considering to try some SR T3.