It does not have to be 24 hours. For you I would just defer your morning dose until after the blood draw. The intent is to avoid false high results. T3 in particular reaches full effect of that dose on serum levels in about 3-4 hours, so you can understand the need to defer until after blood draw.
I was reading your question re timing of getting thyroid labs and I had a look back at some of your earlier posts. It really is heart breaking to see that after two years your doctors have not been able to get your thyroid meds sorted out and you are still hypothyroid. So I thought I would send you a couple of quick comments.
First on the 24 hours business. Most people take Synthroid or other T4, and they usually take one pill in the morning. So they want you to take the pill in the morning and get the labs the next morning before you take the next pill. So in their case it would be about 24 hours. You are doing it differently, so you have to ask what is the principle behind setting the timing. The principle is that you want to take the labs so that they capture the lowest blood thyroid levels that you will have through any day if you follow your particular daily regimen. The lowest level will be at the time which has been the longest time since you took a pill. In your case it will be in the morning just prior to the time you take your morning pill. If you usually take your pill at 6 am, then you might have to wait until 8 am when the lab opens. It good to get into the habit of getting labs at the same time of day.
Now on your labs. It is very obvious from you labs that your T3 is too low and you are having hypo symptoms. You mention palpitations - that is a hypo symptom too. It is easy to find medical research on the web where hypo patients had palpitations and it stopped when they took enough thyroid meds.
Your doctor has seen research reports that show a correlation between hyperthyroidism/low TSH and eventual cardiac problems. But those people weren't taking NDT. But your doctor is looking at your very low TSH and hearing that you have palps, is declaring you hyperthyroid. So of course he won't raise your meds, in fact he wants to lower them. A doctor who prescribes Armour/NDT and does not know it drives TSH to a very low number, and therefore TSH should not be used for gauging adequacy of the meds is not really helping his patients. On 2 grains NDT you are getting 76 mcg T4 and 18 mcg T3. I'd bet that 2.5 grains (95 mcg T4 and 22.5 mcg T3) would make a world of difference for you.
Hi Grace... I get where you're coming with the low TSH and I understand your question about whether or not if you don't take your medication the day before your blood work, will your TSH come up enough to get the doctor off your back? Did I get that right?
I've had the same issues with my doctors for about 10 yrs, because my TSH lives in the gutter
(< 0.01). They kept telling me the same things - that I was getting osteopenia because of my low TSH, it was causing heart problems, blah, blah, blah... I was able to do the same thing you did and point out that I had osteopenia prior to becoming hypo (no med, no low TSH, etc) and I've been on blood pressure medications since I was in my 40's, but didn't have thyroid issues until I was 58... no correlation there and my new cardiologist finally "got it"...
As to whether not taking your medication for one day will bring your TSH up "enough" to get the doctor off your back is doubtful... I had to be off my medications for 3 weeks to do a nuclear medicine scan last year and during that 3 weeks, my Free T4 dropped down to 0.6 (0.8-1.8), but my TSH only went up to 4.0. That's higher than it's been in 10 yrs, but not as high as I though it would have gone in 3 weeks without medication. Of course, we're all different and yours may go up more quickly than mine did.
And what do you think my endo said when she saw that my TSH had come up to 4.0 in that 3 weeks? She said that my pituitary gland had "recovered" from being on too high doses of medication for so many years... I mentioned the 0.6 Free T4 and my symptoms of hypothyroidism and she blew them off with a wave of her hand, telling me "those things happen when we get older". She wanted me to stay off thyroid medication and I said "no", so then she insisted that she would only prescribe a lower dose of T4 and no T3... Of course, as soon as I got back on medication after the nuclear test, my TSH scurried back to its home in the gutter, but my hypo symptoms persisted.
Need I say she's no longer managing my thyroid and I've since gotten my dosage back up to where it was prior to stopping it for the nuclear scan...
It won't really "hurt" you to be off medication for a day, but since T3 medication is in and out of your system faster than T4 medication is, you'll feel it, not taking desiccated hormones, more so than you would if you were taking a T4 medication...
Good luck with your endo appointments in January.
I agree with Barb that 24 hours would have very little impact on your TSH because it is the slowest moving of all the thyroid markers. Also I think it would be better to use your January labs to test at a higher dose - read on.
Since my last comment, I have looked in detail at all your labs and symptoms since inception and I think it is very unfortunate that your doc moved you off the 100 + 15 dose. It looks like you were on 100 + 15 for 5 or 6 months in the first half of 2018.
You have 2 labs on 100+15, March and May 2018:
FT4 - 1.23 and 1.29 midpoint of reference range is 1.3
FT3 - 2.98 and 2.9 midpoint of reference range is 3.2
These labs are very near midpoint and would be like thyroid heaven for a lot of thyroid sufferers. IMHO these are the best of all your labs, and you made several comments about your symptoms diminishing and some gone. The doc should have left you there longer; it takes a long time to get back to normal after all what you have been through.
You have gone from good labs on 100+15, to low T3 on 88+15, to even lower T3 on NDT 76+18. Those are big drops in meds and it is no wonder that your symptoms returned and are getting worse and you are feeling crappy. I know it is not you making these changes, it is your doctors, but any reasonable doctor would see that you are clearly hypothyroid.
It's not my place to tell you what to do, but if I was you I would either go back to 100+15 or go to 2.5 grains NDT which is pretty close (95+22.5). And I would do it ASAP. You do not need to be consigned to hypothyroid hell forever.
I don't agree that TSH is the "slowest moving of all the thyroid markers." TSH can fluctuate as much as 70% over the course of a single day so it's not necessarily "slow moving". The reason I don't feel like staying off meds for a day is going to impact it that much is for the very reason that so many other things, besides thyroid med can impact it... it's been a while since I read gimel's entire paper, but I think a lot of this is addressed there. IMO, because your thyroid levels are already on the low side and your TSH is also low, it's not likely your levels will go low enough to increase your TSH over a 24 hr period. In addition, you have other conditions and take other medications, so there's a good chance they could be affecting what's going on.
You said that your bone scan is, at least partially, if not, entirely, what's putting your doctors into a tailspin about the TSH issue. Again, gimel's paper discusses the fact that when on adequate amounts of thyroid hormones TSH is often suppressed. There's plenty of research that debunks the theory that TSH determines bone loss... Again, I can use myself as an example, because I actually rebuilt bone I'd lost "after" I became hypo and "after" my TSH plummeted into the gutter... I did this via a routine of daily exercise, diet and supplements. A higher metabolism, in general will cause increased bone loss; it's not the lower TSH. As I explained to my endos (the first one listened, got the message and didn't worry about it; the second one refused to listen and she's been kicked to the curb) as well as my pcp - all one has to do is look at Free T4 and Free T3 levels, along with weight and other hypo symptoms to know that I, and you, are not hyper, and that we do not have overactive metabolism... I've since lost some bone due to higher metabolism and not keeping up with my exercise adequately.
I haven't gone back and looked at all your labs and/or posts, so I'm not familiar with where your levels are within the ranges... hopefully, you've kept notes and can determine at which point(s) you felt best and try to keep your levels within a certain range.
Unfortunately, when doctors are determined to dose our medications by TSH, only, there isn't a lot we can do about it. Sometimes, the only options we have are to keep trying different doctors until we find one that will listen to us. It's also important to remember, it's not always an endo that will be our best ally... in my case, it turned out to be my cardiologist who understands that hypothyroidism affects the entire body and is just as bad for the heart as hyperthyroidism. It was unfortunate my endo refused to listen to him so I could no longer deal with her, but my pcp did listen so I transferred management of my thyroid to him and although it's not "great", we're doing okay.
The following link will give you a lot of good info to review and discuss with your doctor.
Grace - yes, I see that you are in a difficult situation with your doctors. I dunno if you have tried this trick to find a new doctor - go to your pharmacy (or every pharmacy in town) and ask the pharmacist if he/she will give you the names of any doctors in town who prescribe Armour. And also ask the pharmacist which doctor he/she would go see...
WRT your experience on the 112 synthroid - it appears that this was the first T4 that you had. I believe that you were still having lingering effects from your Graves disease and surgery at that time, and if you took 112 now your experience would be different.
Great advice all! It's been 8 years since I was educated here about all that has been discussed above, yet to this day, I do not let any doctors test my thyroid levels because they'd freak out over my TSH, I CAN'T. How is it that it is still this way? I have been lucky up to this point that my GP just follows an old prescription and I test myself---but for what you are dealing with Grace, I am so sorry. I feel like endos and doctors need to go back to school and go over these things- they are really hurting a lot of people. Good luck to you, I hope you can get back to the level you need!