Thyroid UK

T3 increase - feeling worst

You can see my previous posts and you will note that I have been seen by an endocrinologist who says I should double by T3 from 20mcg to 40mcg and then see him in 2 months time.

I showed him blood tests I had previously done which included FT3 and he also had up to date figures from my GP which of course didn't include FT3 but showed FT4 and TSH.

So my last FT3 was high ie above range 8.9 when the top of the range would be 6.5

The FT4 was low obviously because I don't take T4 and showed as 2.6 ie very low

The TSH was 3.7 which the endo considered upper normal.

Im taking the increase in T3 very slowly ie im trying to increase by 6.25mcg every week.

I feel dreadful and Im wondering if I should even be increasing it although I had symptoms that made me feel horrible anyway.

Basically my ankles and feet are swelling. Only prevented by taking a diuretic. My bones hurt even more than they did in fact all over my body as opposed to just my legs. A bit like I was when I was on T4 which meant I wasn't converting it.

I feel really hot and Im putting on weight rather than losing it. I have air hunger too.

Are these symptoms indicative of me just getting used to the increase or should I just cut back do you think.

I don't want to ask my GP because he has always been anti T3 and he now has a letter from the endo telling him Im someone who can't convert T4 to T3 and I should be monitored and treated with T3 along.

What does anyone think?

6 Replies


What was the FT3 result and range which made your endo recommend you increase to 40mcg?

If you took T3 before the blood test it will peak in the blood for up to 6 hours giving a high result. If you left 12-24 hours between last dose and blood draw you were over mediated to have FT3 8.9 but TSH 3.7 indicates under medication. Confusing!

Unfortunately, feeling hot, weight gain and ankles and feet swelling can be due to under and over medication.

1 like

I know, how irritating. Yes I left a good gap between the dosage and the test. The FT3 range and result above is the figures you're asking for. The endo had all those figures but was going by how I felt as opposed to the figures I think? Im a bit worried though to be honest. Its taken all this time to get an appointment with him and Im not sure I feel right now.

p.s. one of the figures 6 months ago had an FT3 of 22! But the TSH was 9.5! He wants to assume that was an incorrect reading as opposed to being my actual figures. But he still is suggesting I increase even though the FT3 is still "over" the finish line of 6.5.

What do you think?


As you have Hashimoto's, are you gluten free?

Also what about levels of Vit D, folate, ferritin and B12?

1 like

I am strictly gluten free. I take Vit D and B12 but I haven't had the levels tested.


It might be a good idea to check folate, ferritin, and if taking enough (or too much) Vit D and b12.


Are you taking any other supplements - prescribed or not? There were posts recently about biotin causing abnormal blood tests - maybe others can cause similar problems. My private doctor asks patients to stop taking supplements 48 hours before blood tests.

Just a thought.

Personally I would hold back a bit on the extra T3 if it makes you feel bad.


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