Thyroid UK
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Getting back on T4/T3 combo after T3 only

Hello all,

Since I haven't had any success with my T3 only regimen, I decided to try adding T4 to T3. How should I proceed?

I take my T3 in the morning, one dose only. I am thinking of taking T4 in the evening, at that time I won't have such suppressed TSH and some conversion can take place.

Thank you!

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YulianaRossenova,

It's the amount of T4+T3 you take which will suppress TSH not splitting it into 2 or more doses throughout the day. If you are comfortable taking T3 in one daily dose it is simpler to add T4 to that dose.

Do you have thyroid results and ranges for when you were taking T4 only and what dose T4 were you taking?

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Clutter, I have always had quite decent blood results while on T4, however some of the time while on T4 only I had my hypo symptoms (skipped beats, etc...) even though my results looked OK.

While on T4 only I need a very high level of FT3 to feel good, borderline and over. My last results on 50 T4 only were: TSH -0.55, FT4 - 19.40 (12-22), FT3 - 4.99 (3.10-7.10) and I was feeling like hell, having constant skipped beats and fatigue. My FT3 does not go up as much as I would like it to while I am on T4 only, that is why I thought I had a reverse T3 problem and don't convert adequately, but my rT3 is mid-range.

After starting 12.5 mcg T3 with 25 mcg T4 I felt even worse than I had on 50 T4 only. That is why after 2 weeks on that dose (T4+T3), I decided to stop T4.

I have never gone above 75 mcg T4. I spent a year on 42.5 (50, 50, 25) T4 and I was OK (no skipped beats and other symptoms) 10 out of 12 months on this dose.

I think I will never be OK again. Maybe I had to come to terms with my hypothyroidism and live like that. :(

So you suggest taking both T4 and T3 together in the morning? Wouldn't they compete for the cells' receptors. I am afraid to try T4 again but on T3 I have only ups and downs with no full recovery in sight.

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YulianaRossenova,

I had ectopic beats and awful palpitations on Levothyroxine only and FT3 was below range. Adding T3 to Levothyroxine calmed the adverse effects Levothyroxine only caused and raised my FT3.

I don't think you needed to reduce Levothyroxine from 50mcg to 25mcg. I think adding 6.25mcg - 12.5mcg T3 to 50mcg T4 might have been helpful.

T4 and T3 don't compete for receptors.

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Continuing taking some T3 with the T4 will aide conversion if morning dosing is more convenient.

I have a very suppressed TSH ( secondary hypo) so I take a combination of T4 and T3.

I have virtually no conversion but I do feel much better with T4 in my system. I don't know why that is?

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joesmum, how much T4 and T3 do you take?

Have you ever tried taking T3 only? What was the outcome?

I don't mind taking T4 in the evening, I would do anything I have to in order to feel better. I just want to know which the best way taking T4/T3 combo is.

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YulianaRossenova,

The BEST way is the way which suits you. There is no advantage to taking T3 in the morning and T4 in the evening but as long as you observe that T4 and T3 are taken away from food, drink, supplements and medicines you can take them whenever you like.

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Thank you, Clutter! :)

So we both share one symptom (ectopic beats). I don't have palpitations when undermedicated, on the contrary I have a very slow heart rate and thousands of skipped beats.

I get palpitations when I am slightly overstimulated by too much T3. And then I have less than 5 skipped beats a day, lol. So both a little hypo and hyper at the same time.

I thought T4 and T3 competed for receptors, that is why I assumed I was rendered so hypo when adding T3 do my reduced T4. My first assumption was a high rT3 and my second one was - competition for receptors.

If I take 50 mcg T4 continuously I am afraid that my FT4 will go over range. Is that dangerous?

I know it is not so dangerous for FT3 to be little over range since one feels good, however I don't know about FT4 over range.

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YulianaRossenova,

Your FT4 19.4 was good but no where near being over range when you were previously on 50mcg so there's no need to assume it will go over range if you resume 50mcg. Adding T3 to 50mcg will probably result in slightly lower FT4 as the T3 tablet aids conversion of T4 to T3.

It's not dangerous for FT4 to go over range and some people on Levothyroxine need FT4 over range to deliver reasonable FT3. Read Treatment Options in thyroiduk.org.uk/tuk/about_...

FT3 should remain within range as FT3 over range for long periods increases the risks of developing atrial fibrillation and osteoporosis.

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Thank you so much, Clutter, I didn't know that.

However some people feel at their best with FT3 8 or 9, where 7.80 is the upper limit. I, myself, sometimes had FT3 slightly over range when my thyroid was still working by itself. Is that case dangerous too?

My FT4 also was borderline when healthy.

Since FT4 can go as high as 28, I might even try a higher than 50 mcg dose. I tried with 75 mcg T4, but I was getting more and more hypo... I don't know why, I was on T4 only back then.

I am wondering whether I have some sort of resistance to thyroid hormones. However since T3 alone did not help I am forced to go back and give T4 another try.

Since T3 lowers TSH how will T4/T3 conversion happen and won't T4 pool instead of being used?

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YuliannaRossenova,

I can only repeat that FT3 over range for a long time increases the risks of developing AF and osteoporosis. Presumably the more over range a person is the greater the risks.

Why don't you try 50mcg T4 + 6.25 - 12.5mcg T3 for 6-8 weeks before trying higher doses of T4 and T3. Because some people need FT4 as high as 28 on Levothyroxine only doesn't mean FT4 28 is desirable for everyone. Being over medicated with high FT4 made me feel very unwell.

It's more likely that you are not yet on the right combination of medication and right doses than you have resistance to thyroid hormone.

Both T4 and T3 lower TSH. TSH drops when sufficient T4 and T3 are detected and rises when not enough is detected. Your conversion on 50mcg T4 appeared to be good with FT3 4.99 and adding a little more T3 will raise FT3 close to top of range. TSH is not the only way conversion happens and taking T3 direct overcomes poor conversion anyway.

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Clutter, my FT3 before starting T4 was 4.50, and after 6 weeks on 50 mcg T4 FT3 was 4.99.

Isn't that too little raise for 6 weeks? In the meantime my FT4 went up by 5 units.

Are you on T4 to T3 as well?

And one more question: Is it better to stop T3 for one day before starting T4? Can I start T4 without stopping T3, I feel hypo enough already?

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YulianaRossenova,

There's no need to stop taking T3 when you add in T4. It will take 7-10 days for the T4 to be absorbed so you might want to continue taking your current T3 dose for a week.

FT3 doesn't rise as quickly as FT4 and I think any rise in FT3 is good after only six weeks.

I've been taking T4+T3 for almost 3 years.

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"FT3 doesn't rise as quickly as FT4 and I think any rise in FT3 is good after only six weeks."

I didn't know that as well, although it seems logical since FT4's reference range is about 2.5 times broader than FT3's.

I was feeling as hypo on FT3 4.99 6 weeks after starting my T4, or even more than before starting T4, on FT3 4.50. I had great improvement of symptoms in the first 2 weeks into taking T4 and then suddenly I went very hypo again although FT3 was rising. T3 alone cannot render me euthyroid. Taking it before waking makes me really hypo, no matter how high а dose I take. Taking it in the morning upon waking is better, I don't know why, but I still am hypo. A higher dose makes me a little overstimulated. I really don't know why I cannot get better.

That is why I suspected some sort of resistance.

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YulianaRossenova,

You didn't become hypothyroid in a few weeks and your symptoms aren't likely to resolve in 6 weeks of taking 50mcg Levothyroxine. Symptoms often lag behind good biochemistry by several months. It can take some people up to a year for most hypothyroid symptoms to resolve.

Impatience to feel well, which is understandable, has caused you to make assumptions that you have high rT3 requiring T3 only which wasn't true and after quickly raising T3 doses without improvement you are now suspecting resistance to thyroid hormone. You need to adjust thyroid medication slowly and gradually because otherwise you will be swinging between over and under medication and symptoms will not improve until your metabolism stabilises.

In addition to optimising thyroid levels and medications it is usually necessary to optimise ferritin, vitamin D, B12 and folate levels.

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You are right, Clutter. Thank you for sharing your experience.

When I started 50 mcg T4 for the first time in my life, my symptoms disappeared 2-3 days after starting, literally. Now they cannot go away for months.

How can you account for that?

Also I am working towards optimising the levels you mentioned, although my ferritin is borderline low (4 months postpartum), whereas my iron and the other things from the full iron panel are OK, iron is even in the upper range (was in the lower range 1 month after I gave birth).

I have MTHFR mutation which may explain this discongruity - low ferritin, high iron. I don't have hemochromatosis.

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YulianaRossenova,

It's likely to be placebo effect if symptoms resolved in 2-3 days and then resumed. It takes 7-10 days for Levothyroxine to be absorbed before it starts working on symptoms and up to six weeks to feel the full impact of a dose.

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It was not placebo effect, Clutter.

I had been having skipped beats and fatigue every day for 1 year, my blood results were OK, TSH about 2,5!!!, and I was pronounced healthy by doctors. I did not know anything about thyroid back then and was told my skipped beats were due to anxiety, although I was not anxious at all, lol.

I fell pregnant and started taking T4 to lower TSH. I did not know I was hypothyroid, I thought I needed T4 only during pregnancy. And then the skipped beats stopped within 2-3 days after starting T4. Later into my pregnancy whenever I lowered the dose a little looking only at TSH, my skipped beats reappeared. I made the connection a couple of months later and doctors were still telling me then that I cannot be hypothyroid with these blood results and there is no connection between the disappearance of skipped beats and T4.

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YuliannaRossenova,

If it wasn't placebo effect why did the symptoms resolve for 2-3 days and then return? TSH 2.5 is within range but is high enough for many people to feel quite symptomatic.

As long as thyroid levels are within range most doctors seem incapable of believing symptoms are thyroid related. Before my thyroidectomy levels were euthyroid but TPOab were elevated. My doctors said symptoms were non-thyroidal because I wasn't hypothyroid and having elevated antibodies didn't cause symptoms. Symptoms resolved post thyroidectomy which confirmed my opinion the doctors were wrong.

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Because I lowered T4... due to TSH 1. I was told so by doctors... Ohh... I made the connection later on. AS soon as I lowered T4 to 25mcg, skipped beats returned within less than a week. I am telling you I did not know back then I was hypothyroid, or that my skipped beats were thyroid-related.

Now 50 mcg T4 just doesn't work the way it used to in the beginning.

Actually Shaws and Greygoos suggested my heart flutters might be due to low FT3 2 months ago. And they were right.

So, I did not know anything and it was not a placebo effect, maybe I processed T4 very quickly, I don't know, but thinking back to that time I can say I felt the effect of starting T4 and then lowering the dose in less than a week.

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The cardiologist I saw told me that palpitations weren't faster beats but just ANY awareness of your heart beat - too strong, too slow, too fast, skipping, missing etc, so your ectopic beats are also palpitations. That means you DO have palpitations when undermedicated, as do I - just that their nature changes.

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I see, Angel_of_the_North. So I do have palpitations whenever under or overmedicated, however when over I experience rapid heart rate.

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According to my cardiologist, it doesn't have to be rapid. Normally, you don't notice your heartbeat unless you deliberately concentrate on it.

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Yes, so the term "palpitations" cover: rapid heart rate, awareness of one's heart rate without it being fast, and ectopic heartbeats. I have the last when undermedicated and the first when overmedicated.

In Bulgarian we do not have so many words, actually we don't have the cover word "palpitations", so it's a bit easier to distinguish between all of them, at least for me, lol.

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I am currently taking 100 mcgs levo and 15 mcgs of T3. This is not necessarily my final prescription because my endo keeps playing around with the mix. I am secondary hypo so bloods are slightly harder to interpret.

My endo would not sanction a T3 only regime and I wouldn't challenge him because I'm extremely lucky to be under his care. He's one in a million!

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Thank you, joesmum and Happy New Year!

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