Tsh close to zero but t3 and t4 normal on meds?

[SarahLou30]

Hi there,

My doctor added t3 about a month ago since my free t3 had been consistently low for over a year. She also lowered my synthroid. I went from about 100mcg synthroid daily to 85 mcg synthroid and 10mcg t3 (split into two doses of 5). Finally have more energy and less shortness of breath when exercising. Just got labs back and tsh is very suppressed at .09 (range .35 - 3.600) and it was 1 before getting on t3). My endocrinologist wants to lower my synthroid to 75 mcg but I’m worried this will lower my t4 too much. Is it possible I need my tsh to be this low to have optimal t3 and t4?

I hadn’t taken synthroid for 24 hours and it had been 16 hours since last t3 dose.

Recent labs:

Feee t3: 2.6

(Range 2.4-4.2)

Free t4: 0.86 ng/dL

(Standard Range .70 - 1.37 ng/dL)

Of note

I also take 2000 IU vitamin d daily and am on a strictly gluten free diet.

Thank you for any input!

Sarah

[tattybogle]

Yes it's possible .... the T3 medicine in particular will often lower TSH to that sort of level .. T3 medication at any dose often does. it does not necessarily indicate overmedication , the fT4/3 levels are a better gauge of that .

As long as fT3 /4 are in range , low TSH in itself is not necessarily a problem. (and your recent fT3 and fT4 are barely even IN the range let alone too high )

0.09 is not actually 'supressed' it's 'low' .. there's a significant difference.

This post will be helpful healthunlocked.com/thyroidu... ... lots of useful links on the subject of low TSH.

My rely to it has a link to some evidence that "low but not supressed TSH 0.04 -0.4 "(on Levo) has no greater heart /bone risks than TSH 0.4 to 4 does .

And it also links to several other posts with useful discussions.

I've had TSH 0.05 ish for about 15 yrs on just 150/ 125 /112.5mcg levo .My fT4 has usually been at the top of the range, occasionally a little over, sometimes comfortably within range.

my fT3 has never been over 50% of the way through the range.

[SarahLou30 in reply to tattybogle]

Thank you so much for that helpful information! I really appreciate it! I will bring all that up with my doctor.

[tattybogle in reply to SarahLou30]

Good luck.. I think your best approach is to point out how very low in range your Recent fT3 and fT4 were on 85/10 and that surely lowering levo any further will reduce fT4 and possibly also fT3 to a point that they may not even get into the reference range.

And that since you feel so much better you 'd like to leave things as they are for 'a few months' more to optimise the health benefits of being better able to exercise, and review it then.

Let them know you understand and accept the 'risks' of low TSH. (since you are unlikely to be able to persuade them that there are no risks.. they've had it hammered into them since medical school that low TSH means 'you're all gonna die' )

That should hopefully make them feel less threatened about the possibility that they are overmedicating you and you'll be back to sue them... and a 'trial of staying on same dose for few months' is less scary to them than sanctioning it forever.