Thyroid UK
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NDT + synthroid?

I started Nature throid 1/4 grain per day.

Didn't take more cause I felt my heart rate is a little faster. But I still take it because I realise with it I am more motivated and able to go jogging without feeling too slugish. My report is out. My TSH got better but my T4 got lower. Can/should I mix my synthroid with NT?


Free T4 - 12.7 (9.0-25)

TSH 3.11 (0.40-4.70)


Free T4 - 14.3 (9.0-25)

TSH 3.57 (0.40-4.70)

1 Reply

Bellameow, you're probably getting racing heart because your TSH is high. Most people on NDT have low or suppressed TSH. You should increase dose in 1/4 or 1/2 grain increments every 2 weeks until you are on 1 grain. Hold at 1 grain for 6 weeks and have a thyroid test, including FT3, before increasing further. FT4 may have dropped because you are not yet on sufficient dose. It is usually lower in patients taking NDT or T3 than those on thyroxine but I doubt the 2.5mcg in 1/4 grain is enough to lower FT4.

You can add 25mcg Synthroid instead of increasing NDT dose if you prefer. You'll probably need another 25mcg dose increase in 6-8 weeks.


I am not a medical professional and this information is not intended to be a substitute for medical guidance from your own doctor. Please check with your personal physician before applying any of these suggestions.


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