Thyroid UK

raised heart rate, low temp, trying to raise NDT

hi, all. i am still in the process of trying to optimize on NDT. recently raised from 2.75 grains to 3 grains. was fine and doing better on the increase for one week. last night, began to have raised heart rate--98 beats per minute (and pounding) while just lying in bed; this morning, same thing--heart rate 96 while just lying in bed (but not as much pounding). also felt severe emotional distress/stress yesterday. on the other hand, my temp has been lower than usual--well below normal. any thoughts? i have decided to skip the NDT today altogether, in case this is from too much T3, but i really don't know what to do at this point. is this an adrenal issue or a too-much NDT issue? my ferritin level is good, so it shouldn't be down to iron.

can't get blood test any time soon so don't know what the labs look like right now.

28 Replies

I would say it looks like too much NDT. I would drop back until you have your bloods checked. Think the temperature can take a while to rise.


Thanks, fixit


Split your dose over the day. 2.75 to 3 grains is not that big a jump and your temp is still low. I doubt the total dose is too high, but your body is absorbing the T3 too fast in one sitting. Try taking 1 grain 3 times a day (not too close to bedtime!) or 1.5 in the morning and 1.5 at lunch.


Thanks for the responses :)

I already do divide my dose and have done for years: 1 grain early a.m., 1.5 grain noonish, .5 at bedtime. Helps avoid the afternoon slump or a flood of t3.

Someone mentioned to me that it sounds like a reverse t3 problem. I'm really at a loss and always have extreme trouble with raises, though I also need them. :( Took no medicine today and felt much better; think I will try again tomorrow at either 2.75 again or 2.75 plus 1/8 grain. Really not sure :( probably need adrenal support, or more time ?


Is your temperature at a stable low or does it fluctuate?

I love Dr. Rind's explanation of metabolic temperature:

Unstable temps: adrenal fatigue. Core temperatures have wide variations. They tend to rise in warm weather and fall in cold weather.

Decreasing variability: with adrenal support, as the adrenal gland function improves, variability decreases (temps become more stable)

Low but stable: after the temperatures have stabilized they still remain low but relatively stable.

Stable and rising: after a period of being stable, the next phase of improvement is a gradual rise in average core temperature.

Stable 98.6º F: This is typical of a healthy metabolic stat

He goes on to explain that if your temperature is low and stable throughout the day then it is hypothyroid without adrenal problems. If it is fluctuating then adrenals are probably at fault.

It would be good to track for a few days before going down the adrenal route. If you do not have an adrenal problem the adrenal supps will make you feel funny.

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thanks so much again! i have been keeping track of temps and maybe it's thyroid brain but i somehow can't figure out what to make of them at all. if you (or anyone) have (has) the patience, could you let me know what these temps might mean?

27 may

11:00 am 97.7

28 may

11:07 am 98.06

12:45 pm 98.04

8:15 pm 98.34

29 may: increased dose from 2.75 to 3 grains

5:35 am 96.62

11:35 am 98.96

11:39 am 98.42

4:26 pm 97.7

30 may

12 pm 97.45

9 pm 97.6

31 may

2 pm 98.04

1 june

12:00 pm 98.06

4:23 pm 96.98

8 pm 97.88

2 june

4:29 pm 98.9 (but was in hot kitchen)

5:00 pm 98.34

3 june

8:46 am 98.2

11:40 am 98.17

5:40 pm 97.6

4 june

5:30 am 97.9

6:55 am 96.93

8:50 am 98.5 (hot room)

11:00 am 98.43

5 june

7:47 am 97.58


Do you have any records before may 27?

After the increase it's clear your body is freaking out.

I wonder if you were mostly stable day to day on 2.75 though.


thanks so much! is it clear b/c of something you see in the temps, or b/c of the heart symptoms i've mentioned? i really don't know what to make of the temps at all. will look for more records now...


May 28 is what "stable but low" looks like:

11:07 am 98.06

12:45 pm 98.04

8:15 pm 98.34

You're fluctuating less than half a degree.

Where as this day:

5:30 am 97.9

6:55 am 96.93

8:50 am 98.5 (hot room)

11:00 am 98.43

There's 2 degrees difference throughout the day. According to Dr. Rind that kind of fluctuation shows that your adrenals are not doing well. Remember that even as you go from hot to cold your body is SUPPOSED to be able to maintain a relatively stable core temperature. That is your metabolism's job!

It may not be that you have a real adrenal problem if you were low but stable before...but that adding in that bit of extra NDT is upsetting them.


thank you so much for all of this! some more temps (records aren't as complete): actually, i am starting to get confused by my own records, but i think it goes like this:

24 april moved from 3 grains to 3.25 grains NDT

29 april reduced to 1.5 grain b/c of bad symptoms

2 may no thyroid meds

3 may 1 grain NDT no problems

5 may started back at 2.5 grains

6 may

3.54 pm 98.6

7 may

morning 98.6

11 may

temps getting higher/better

12 may (2.5 grains NDT)

4 pm 98.3

4.30 pm 98.6

13 may

4.15 pm 98.62

16 may


18 may

9.26 am 97.6

19 may

12 pm 97.86

1.27 98.34

20 may

6 am 97.0

2.33 pm 96.8

21 may

1.25 pm 98.34

4.46 pm 98.04

22 may (on 2.75 grain NDT?)

8.19 am 97.8

1 pm 97.3

24 may (2.75 grain NDT?)

1 pm 97.6


i think the problem is that, in february, a doc added 25 mcg t4 to my ndt plus t3 meds, in order to get rid of my shaking problem (shaking with isometric holds). eventually i ended up, with her guidance, on something like 2 grains NDT, 15 mcg t3, and 25 mcg t4--something like that (i can check my records for the exact amount of NDT). but my throat swelled up and voice got hoarse on the t4, so that was dropped. it all became much much too much at some point and i went off meds completely for some days. then when i restarted i ended up getting rid of the t3 completely, a bit gradually, b/c i felt better without it than i have in like 4 years. i always felt absolutely awful on synthetic t3. after that i decided to just get on all NDT and it's all sort of become a mess since then, though it's still better than life with synthetic t3.


update: skipped NDT altogether yesterday and felt better, no heart issues, and could walk up a hill, which i haven't been able to do for weeks. however, this morning, woke up with pounding heart again, HR 94. this has gone on for an hour now. no idea what to do. skip another day? i already took 1 grain, but the pounding started 1 min. afterwards, so it couldn't have been due to today's NDT. really struggling here.


Palps are a serious thing, I might take a whole week off and see how you feel. How long were you on 2.75 grains before raising?

Some docs titrate you up every 2 weeks but Broda Barnes says you should spend a full 2 months on a dose before raising. Different strokes for different folks...


And the reason I recommend taking a whole week off is because if your body is freaking out, it can be hard to get equilibrium back taking external hormone.

Even if you were FINE on 2.75 before, once you upset that status quo, you will not feel fine immediately going back to 2.75. You may need some time for your body to settle down before taking NDT again.


A long time ago a doc raised me from 1/4 grain to 1 grain quickly and I felt SO strange. Jumping back down to the original dose did nothing. I had to get off NDT completely and go through an awful 2 weeks of pure hypo before I could take it again.


ugh--this sounds awful and i can't even bear the thought of spending more weeks hypo and miserable :(


thanks again, ticktickatick, especially for the temp analysis. so helpful. much appreciated.

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thanks. last time i had this, 2 days off the med seemed enough to fix the heart situation--i already blew it by taking 1 grain ndt today, but i guess i should give it more time. i was on the 2.75 grains for 2 weeks before i raised. things are a bit confused now b/c i had been on 3 grains without a problem not all that long ago, for a bit--then when i had a lot of heart issues i lowered again and reset to 2.5 for a bit, etc. now i am kind of all over the place. i was dying for the increase from 2.75 to 3 and then when i did it, i felt much better for a week, before everything started going pear-shaped.


How long were you on the 2.75 before raising to 3?


thanks- i was on 2.75 for 2 weeks.


I think you might have raised to quickly. I did the same thing as I still didn't feel well on lower, 2 to 3, kept raising till I was on 5. When I was tested I discovered that both FT4 and FT3 were over range, now dropped back to 2 or 3 and approx every other day take 25mg T3 with food as I don't want to absorb all.


thanks so much. i was absolutely miserable at 2.75 and felt better after the raise. this is so hard. do you have any idea if i should go back down to 2.75 or to something lower, or how many days i might need to take nothing for and then reset again? also very interesting that you take extra t3 every other day. my husband just yesterday wondered if i should alternate with days on and days off b/c i seem to fluctuate so much. i am totally lost at this point.


i.e., i felt better after the raise from 2.75 to 3, for about a week. guess, as you're saying, i didn't wait long enough on the 2.75.


I would stay on 2.75 for another 2 weeks, this might be helpful :

Those who start on natural desiccated thyroid have discovered that it can be wise to RAISE by 1/2 grain every two weeks or less to prevent hypothyroid symptoms from returning due to suppression of the internal feedback loop in your body, which can happen if you stay on a low dose too long before raising. Most patients start to slow those raises down in the 2-3-grain area to give the T4 time to build (which can take 4-6 weeks) and show its conversion results..then inch their way up if needed. Some patients end up in the 3-5 grain area when optimal, some on a lot less, and some on more. It’s individual. (Janie Bowthorpe is on 3 1/2 grains, for example)

Also, have you checked your iron and cortisol levels?:

'I once tried NDT and it gave me problems! Why?

There are very good reasons which weren’t because NDT doesn’t work. It’s either because you didn’t raise it high enough, or because you didn’t realize a few things which need correction, and which NDT will reveal, such as inadequate levels of iron or problems with your cortisol levels. And the latter have nothing to do with “being in the normal range”. Read the link carefully and find yourself. Because NDT does wonders!!'

Also magnesium and selenium help conversion T4 to T3 and also how many of the following tests have you had:

1.Thyroid Peroxidase Antibodies (TPOAb)

2.Thyroglobulin Antibodies (TgAb)








10.Vitamin D3




14.basic pituitary hormone function tests.


than you so much! much appreciated.


You're welcome, hopefully others more knowledgeable than me will soon chip in.

By the way, not sure I mentioned this but over range symptoms are similar to hypothyroidism symptoms.


yes, i have felt terrible/hypo when over the range (free t3) too! (and thanks again.)


Best of luck xxx


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