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Do you skip your thyroid meds on lab days?

I went for my labwork today. Hopefully, I will get my meds raised because I still feel hypo.

My endo's nurse told me not to take my Synthroid before my lab this morning. I thought that was weird, but I took my Synthroid after labwork.

The lab tech said that I would not get an accurate reading.  Should it make that big of a difference since I have been consistend with my Synthroid for the past three months?

Any thoughts?

Thanks!
:) Tamra
39 Responses
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1157646 tn?1343967128
lol....yep, im getting there!!!  Im learning quite quickly - i got no other choice but to learn quick!!!
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Avatar universal
You are LEARNING Nat lol !
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1157646 tn?1343967128
Well, I saw my endo once before surgery and he reccommended a FNA so I had that, went back to him then he recommended surgery because the results came back non conclusive.  Saw him again in the pre-op area of the hospital, saw him for follow up and at the 3 month follow up basically he said he doesnt need to see me again unless I have issues....that was after he doubled my dose....useless!!  

He didnt even tell me the T4 med had to be taken on an empty stomach...that was the GP....he told me nothing, he gave me a script and said take this...damn dr's!!
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Avatar universal
Same here..my Endo got fired after the 2nd appointment. The first was for RAI, the 2nd was for followup.
I have worked with my GP ever since.
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1157646 tn?1343967128
lol....but Im starting to agree with you Deb!!  My GP is being more useful than my endo!!
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649848 tn?1534633700
COMMUNITY LEADER
Good one Deb -- and so true for most of them.  They sure aren't going to forget about the bill............lol
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Avatar universal
Endos tell you nothing usually...only when the Bill is due! lol

Opps soz..joking with you lol xxx
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Avatar universal
Some doctors recommend not taking T4 meds before bloodwork, others say to take them.  The really important thing is to be CONSISTENT...either always take them before labs or never take them before labs.  It's also important to have blood drawn at approximately the same time of day each time you have labwork since there are some circadian variations.

I think it's best to take meds or not according to what the doctor ORDERING the tests tells you to do.  That way, in addition to being consistent with yourself, you are giving him lab work consistent with what he is used to seeing with other patients...we don't want to confuse him either.

Since T4 takes time to build  (and therefore also to leave) in your system, skipping your T4 meds until a few hours later than usual is not going to affect your levels appreciably.  T3 meds are a different story and should not be taken before labs.
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1157646 tn?1343967128
My endo never told me anything about meds on lab days.....it was only the day before the last lot of labs I with my dad to an appt with a dr (not a endo!! ) and he said for me to not to take the T4 till afterwards....

Why didnt my endo say this - is it still debatable whether it should be taken or not or did my endo not tell me something important and could all my previous blood work be not 100% reliable???  
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Avatar universal
i recently had to have a cardiac procedure, which turned out great and blood work was done at the hospital and my unsymphathetic primary care got a copy of the lab.  i had a tsh of .64 and free t4 of .97. and i am on 75mcg and i am finally feeling normallllll and finallyn after 6 months of trying am losing weight! now the doc is saying he wants a blood test because he thinks i should decrease back to 50 mcg, which i felt absolutely crappy on and tired as hell. he doesn't treat symptoms, just numbers.  i also have a endo who bumped me to 75mcg from 50, and she will retest in 3 months to make sure i stay in the 1.7 tsh range, arghhhhhhhhhh...my cardiologist agrees i need to be on the higher dose, but tells me to have the endo discuss it with the primary. im so upset...i feel so good on 75mcg, have expressed so to the primary.
now the bases of my inquiry...can i skip 1 day before the lab and the morning of the lab and will this change my lab so it looks "better" to my primary? its a damn shame we have to fight and struggle with these drs, to agree!!!!
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Avatar universal
I take it right after the blood test !!
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393685 tn?1425812522
yes... yes and YES - I skip prior to testing.
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Avatar universal
Unfortunately, where I live we have the second highest diabetes rate in the country, so we have too many endos that specialize in only diabetes.

I wonder if we could start a list of recommended endos on this forum. I noticed that the About Thyroid site lists my mom's endo, and she only treats TSH. She also said that Hashi antibodies don't mean a thing, and that they could come and go from day to day; therefore, treating Hashi is the same as treating hypothyroidism. I wish someone would explain this theory to MY antibodies.

:) Tamra
Helpful - 0
798555 tn?1292787551
Yes, I too just found a doc that treats by symptom and will go with dessicated (what I need). He is an MD but does not accept insurance and could retire now if he wanted.

The younger doctors I have met have been TSH and synthetic t4 brainwashed.

This, unfortunately, makes a big difference if I move someday. Not to many stay here forever. There needs to be a better doc list than the one on About Thyroid.

Helpful - 0
907968 tn?1292622204
  I would assume it all depends on the specific lab doing the work(?) but do you know if it is procedure to have the time of day the blood was drawn on the lab paperwork handed to your Dr?  I know I took all my med.s at the usual time but I don't remember if I took the ten minute drive to the lab right after or if I waited til late afternoon.  If it is usual practice then I'll contact my Dr and find out the time.
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Avatar universal
Luckily, I don't have to be sneaky with my new endo because he treats my symptoms. If only all doctors would be like him. He's getting close to retirement age, which scares the heck out of me.

:) Tamra
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Avatar universal
I didn't suggest to skip the med entirely. Just get your labs in the morning and take the T4 after your labs.

:) Tamra
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793305 tn?1493925518
This is very interesting...I guess my dr's have never said to or not to, but I am on T4 only.  I would think you would want to take it and keep your levels consistent, might it not drop if you don't take it?  I never miss taking my meds.  I take it like clock work every morning at 5 a.m.  
So next time...I'll ask.  : )
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798555 tn?1292787551
Ha!........"So if you are wanting a bump, it is to your advantage to wait on taking the meds until after the bloodwork."

Thats funny! My exact thoughts too, but I didnt want to push the fact that we sometimes have to be 'sneaky' with uninformed docs just to get optimal!  Why do we have to do this #@?#!! ,     errrrrrr!

LOL
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Avatar universal
My endo, the fourth one after quite a search, knows a lot about thyroid disease. Initially, I had asked the forum if it was normal to wait to take the thryoid meds until after bloodwork, because my endo's nurse had told me to hold off on the meds. After the labs I spoke with my endo, and he does advise all of his patients to wait until after bloodwork to take meds.

Which means that if the lab opens at eight, no coffee or food until nine!

Blah!

But my FT4 was a 1.0 when I'd skipped the meds. My FT4 was also a 1.0 a month earlier on .25 mcg less hormone. So if you are wanting a bump, it is to your advantage to wait on taking the meds until after the bloodwork.  

:) Tamra
Helpful - 0
798555 tn?1292787551
The time a doctor insisted I do an "unscheduled'  lab blood draw right after an appointment with him, screwed up the consistency with all my previous labs. It read higher than I usually like (I like higher free T3 to begin with) on the frees, and he wanted to lower my dose.  I gave him the 'symptom' speech and he left my dose alone. I had another lab weeks later consistent with my previous labs. So, yes meds two hour before without a doubt, messed up my lab results.

Inconsistent test times are not worth it. Need to compare apples to apples. Any  inconstant scientific test in any other industry would be tossed out the window.

**BUT- Years ago on T4 only, I took my med in the morning , 6 AM before labs but CONSISTANTLY had lab work at 4 PM, always. I think you can spread the time frame out on only T4.**

But for a MORNING lab, like others, I would not take my meds again beforehand, T4 or combo.

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1144849 tn?1395455166
This is a good question .. I was not sure either so I asked my doctor so that I will know when I go in for labs soon. I am on Methimazole and the doctor said to stop taking it 3 days before labs.

McMillan
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649848 tn?1534633700
COMMUNITY LEADER
Maybe with just a T4 med, it wouldn't make that much difference, but it will with a T3 med, such as cytomel or a T4/T3 combo because the T3 goes directly to work.....I guess I'd rather be safe than sorry.........
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Avatar universal
I have been told that it would not make a difference one way or the other if you take it or not before lab work. I have never been told not to take it.

Now if you miss more than 2-3 days in a row it would.
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