Taking thyroid replacement before blood test

[tangolil]

Should I take my Levothyroxine the morning of my blood test to determine whether I am on the correct dose?  Advise me, please.

[shaws Administrator]

Allow approx 24 hours between your last dose of levo and the test. No thyroid hormones before the blood test as it skews results. Also you should fast as well although you can drink water and the test should be as early as possible.

[tangolil in reply to shaws]

Thank you so much for this swift reply.   I took my usual dose last time I had a blood test and my GP reduced the dose on the basis of the results which showed elevated T4, since when a lot of my pre-medication symptoms have come back.  I mentioned this to my GP who told me that taking my medication before blood test would NOT interfere with the result!  You have restored my faith in my 'gut feeling'!  I will follow your advice,  Thank you again.

[shaws Administrator in reply to tangolil]

Who knows best - a Forum full of thyroid patients who've had the same results as you i.e. meds before tests. Doctors do not know anything about blood tests, how dosing before can affect results, adjust hormones willy/nilly according to the TSH alone. Not enquiring or taking notice of remaining clinical symptoms.

So, make the earliest possible appointment, leaving approx 24 hours between last dose and test (I usually put tablets elsewhere the day before so I'm not on automatic pilot and take meds. Also fast a.m. although you can drink water.

You end up on a merry-go-round - increase/decrease/increase/decrease

[tangolil in reply to shaws]

Too true!  I have been lucky in the past with my dose suiting me very well but now, with the reduction, I am feeling as I did before being diagnosed!  This has had a marked effect on my ectopic heartbeats which so concerned my GP that he thought I was in AF and sent me for an ECG. All is well .... and AF is not my problem!  GP also refuted my suggestion that lowering my dose could cause this and said that only an increase in meds would have that effect ..... so he's doubled my meds for high blood pressure instead!  As you say, Doctors know nothing about blood tests.  Thank you for your reply.

[shaws Administrator in reply to tangolil]

Our heart struggles, particularly if our dose is too low. Your h.b.p. probably due to it as well. I've had umpteen ECGs etc on levo.

I'd make my own decision of how best to treat my hypo if I was feeling fine before the reduction. 

If your GP tested your FT3 he'll probably see it is on the low side but will probably say he cannot test FT3 and considering T3 is the only hormone required by our receptor cells - it confuses me that they know very little and we've to do a 'search' for info that confirms our instinctive thoughts.

(I am not medically qualified - just have the experiences many on this forum have/had. I am well now thankfully. The more I reduced levo and increased T3 the better I became). Many find the addition of T3 to T4 very helpful indeed.