When taking NDT, thyroid tests should be done 8-12 hours after the last dose, not 24 hours. By leaving 24 hours the FT3 result shows a false low.
As your FT3 result is right at the top of the range, it would suggest that you are overmedicated, and that could possibly be the cause of your fast heart rate.
I don't take NDT so am not sure how reductions should be made. I know increases, once you reach a certain level, should be in 1/4 grains so you don't miss your sweet spot. Maybe that is the same with reduction. Perhaps reduce by 1/4 grain and retest in 6 weeks to see how your levels have altered and how you feel. Then if necessary, reduce by another 1/4 grain and retest again 6 weeks later. You may not be too far away from your optimal dose. But do make absolutely sure that you only leave 8-12 hours after last dose of NDT before blood draw. T3 is not detectable in the blood after 12 hours although it will be in the cells for a couple of days, but it is what's in the blood that is measured.
Hello SeasideSusie, I read your answer above with interest where you mentioned only leaving 8-12 hours from the last dose before testing. I'm on T4 (100mcg) and T3 (5mg) and my blood results have been optimal (or what I have read is optimal) for the past 4 mths. My blood pressure is normal, but my heart rate is raised (often around 100-110). I am feeling much better overall, but am baffled about my high heart rate. I am wondering if I am over-medicated now, especially as when I had my last blood draw, I left 24hrs (not 8-12hrs) from my last dose as I take my T4/T3 each morning.
My recent blood tests were:
FT4 - 18.8 (9.0 - 25.0)
TSH - 0.04 (0.50 - 5.00)
FT3 - 5.9 (3.5 - 6.5)
My TSH is suppressed, but my research tells me that this is due to taking T3.
I'm wondering, after your answer above, if after leaving 24hrs and my T3 is still at the top of the range, whether I am in fact over medicated and whether this may be causing my fast high rate. The other curious thing is I'm putting on weight not losing it, even though my bloods say I'm optimal. I'm a little confused. Any feedback you have would be welcomed.
Leaving 24 hours will give a false low FT3 so your result of 5.9 is lower than it would be if you'd left the advised time gap.
I take my T3 with Levo all in one dose in the early hours of the morning when I need the bathroom. What I do the day before my test is to delay taking my thyroid meds until 9am (I know I will do the test at 8.30am the next day). I take my full dose of Levo and half my T3 dose. I take the second half of my T3 between 9pm and bedtime and that gives the 8-12 hour time gap from last dose of T3.
As for weight, taking T3 isn't necessarily going to make us lose weight, it hasn't made me lose weight but as long as I'm sensible my weight stays stable.
Thank you for your response. So to be clear, my false low of 5.9 - could this mean I'm a little over-medicated since it's near the top of the range on a false low??? Sorry, just trying to get my head around this.
I agree with SeasideSusie also... I think if it were me I would start with dropping half a grain, 1/4 is a safer way to adjust but from your labs I think half grain would be better for your heart symptoms...
Content on HealthUnlocked does not replace the relationship between you and doctors or other healthcare professionals nor the advice you receive from them.
Never delay seeking advice or dialling emergency services because of something that you have read on HealthUnlocked.