Aa
Aa
A
A
A
Close
Avatar universal

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
Sort by: Helpful Oldest Newest
1013194 tn?1296459481
I have not skipped mine when i have my bloods done, but im seeing here that a lot of ppl do, i haven't yet been told to but im thinking maybe i should:)
Helpful - 0
Avatar universal
I have always skipped my dosage the day of my labs.. I had labs done today actually and skipped on it.. I think that as long as you have been consistent with it for the last 3 months then it shouldn't make a huge difference taking it or not for 1 day...  
Helpful - 0
1013194 tn?1296459481
So do you take it at all that day of you labs?
Helpful - 0
Avatar universal
I probably should have but because i ate breakfast and had coffee i skipped on it completely.. I've had exceptions where i skipped for the day but not very often at all.. I only did today because i wanted to eat and drink my coffee after my appointment haha.. but usually i'll schedule my labs for first thing in the morning and then take my meds afterward..
Helpful - 0
1013194 tn?1296459481
Lol ok, well i think i would be wanting my breaky and coffee as well:)) I read on my instructions if you miss one it wont make any difference if you miss three days it will..Dawn
Helpful - 0
231441 tn?1333892766
hi,

i always take it after, not before the labs. particularly as i take dessicated.

your dr's nurse is right. should not take the med before the test. levels may appear high because of the just absorbed dose.

Agree with dawn too that missing 1 day not a big deal - though repeatedly missing days will....
Helpful - 0
231441 tn?1333892766
hi,

i always take it after, not before the labs. particularly as i take dessicated.

your dr's nurse is right. should not take the med before the test. levels may appear high because of the just absorbed dose.

Agree with dawn too that missing 1 day not a big deal - though repeatedly missing days will....
Helpful - 0
Avatar universal
Thanks all! I think the guy at the lab had no idea what he was saying. He's not an endo. I assumed the nurse gave me orders from my doctor, and he seems to know a lot about thyroid.

My last endo didn't tell me to skip my meds, but she didn't seem to know SQUAT about thyroid.  That's why I switched.

:) Tamra
Helpful - 0
499534 tn?1328704178
I have a fantastic Endo who is a Thyroid Specialist.....and he always reminds me  to NOT take my thyroid meds before my labs. I always take them with me and pop them after my bloodwork is finished.
It will give a false flood of hormone in your system if you take it before.  :)
Helpful - 0
Avatar universal
I do the same as Laura.
I take my T4 with me but dont take it until blood is drawn.
I usually take a bottle of water with me and take the T4 med in the waiting room After bloods drawn.
By then I am usually 'hanging out' for the T4 med lol.
Helpful - 0
1013194 tn?1296459481
Why dont all doctors inform you of this:( my last blood showed i was a little high in T4....20.7- range (10.0-19.0) said do you feel hyper, as i didn't he said it was prob because i had my meds an hour before i went, he still didn't say dont take it before you come..
Helpful - 0
649848 tn?1534633700
COMMUNITY LEADER
I do the same as Laura and Deb -- take my T4 med right after the blood draw.  I'm also on cytomel, so absolutely don't want THAT dosage in my system BEFORE the test.....I take a bottle of water to drink with my med and I also take along my coffee mug -- that 30 minutes goes faster than you think..........

My doctors have not told me anything either -- it's just a habit from years of having other types of blood work -- they always say not to take med before fasting blood work......except heart/blood pressure med.
Helpful - 0
607546 tn?1222299144
I did ask my general Doctor because I forgot to ask the Endo. He said unless I get my synthoid put in an IV directly in my blood stream it does not matter if I take it before the blood draw. Now that I'm on Nature throid I do wait until after. I would listen to the girls on the forum they know more than most Doctors!!!
Helpful - 0
Avatar universal
I had a bottle of water and my Synthroid in my purse. After bloodwork, I took it out and the lab tech said I should have taken it before the bloodwork. What does he know????

I'm sure glad I listened to my new endo's nurse. The last endo said nothing about this and my TSH measured 1.2. She was afraid to push my meds, even though I felt VERY hypo. She was the doc who treated TSH, not the frees, so she was CLUELESS anyway. I now wonder if my TSH had dropped because of the Synthroid I'd just taken.

:) Tamra
Helpful - 0
964127 tn?1252375462
I don't take mine until after labs either!
Helpful - 0
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.
Helpful - 0
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.........
Helpful - 0
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
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.

Helpful - 0
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
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
Helpful - 0
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.  : )
Helpful - 0
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
Helpful - 0
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
Helpful - 0
2
Have an Answer?

You are reading content posted in the Thyroid Disorders Community

Top Thyroid Answerers
649848 tn?1534633700
FL
Avatar universal
MI
1756321 tn?1547095325
Queensland, Australia
Learn About Top Answerers
Didn't find the answer you were looking for?
Ask a question
Popular Resources
We tapped the CDC for information on what you need to know about radiation exposure
Endocrinologist Mark Lupo, MD, answers 10 questions about thyroid disorders and how to treat them
A list of national and international resources and hotlines to help connect you to needed health and medical services.
Herpes sores blister, then burst, scab and heal.
Herpes spreads by oral, vaginal and anal sex.
STIs are the most common cause of genital sores.