Hi I’m having a few problems with my endo. I’m on NDT and the last 2 bloods tests were done late afternoon on meds. I began to feel undermedicated so insisted on getting my own bloods done first thing in the morning on no meds and there was a huge difference in my blood work. She raised my dose but doesn’t agree with me so we’ve come to a compromise I do my bloods my way but occasionally her way. Her reasoning is she needs to see how the meds are working! Do I look for a new endo?
Under medicated: Hi I’m having a few problems... - Thyroid UK
Yes, when booking thyroid tests, we should always book the very first appointment of the morning and fast overnight (water allowed) . This gives the highest possible TSH which is needed when looking for an increase in dose or to avoid a reduction. TSH is highest early morning and lowers throughout the day. It can also lower after eating. However, NDT can lower, even suppress TSH which your endo should know if prescribing it.
When taking NDT only there should be 8-12 hours between the last dose of NDT and blood draw. (If on Levo it would be 24 hours.) This is because of the T3 in NDT and the fact that T3 has a short half life. If you take your NDT any more than 12 hours before blood draw you will get a false low FT3 result, if you take it too close to the blood draw you will get a false high FT3.
These are patient to patient tips which we don't discuss with doctors or phlebotomists.
So your last dose of NDT was 19.5 hours before the blood draw. That gives a false low FT3. So we actually have no idea what your normal circulating FT3 is. We can guess that by adding 20% it would be around 5.2 but that is a very rough guess only. FT3 is usually best nearer the top of the range.
However, your TSH is far too hgh for a treated hypo patient, when on NDT it is usually very low or suppressed. FT4 is usually low as well.
She was right to raise your dose.
Her reasoning is she needs to see how the meds are working!
That's popycock. Testing after taking a dose doesn't show how the 'meds' are working. Just shows you how much of the dose you've previously taken that day is left in the blood. What does that prove? She's just trying to sound clever in order to get her own way.
You change the timing of your NDT so that your last dose is 8-12 hours before your blood test. So if your blood test was 8am then you would take your last dose of NDT no earlier than 8pm the evening before, and no later than midnight. I have to do this when I have a test because I take a combination of Levo and T3, so I just change the timing for that one day.
I don't split my dose. When I first started taking T3 I took 1/4 tablet in the morning. When I added the second 1/4 I took it late afternoon, I've never taken it at night. But I got fed up of trying to time food and drink around taking the second dose so I started taking it all in one dose evenwhen I increased further. It didn't make any difference to how I felt so I just take an early morning dose now and don't have to worry about timing anything else.