Thyroid Test


I was taking 2 grains of Nature-Throid. My doctor added 25 mcg Levo since my FT4 was low. Also, my iodine was low. I am taking 6.5 mg i-throid every day to bring up my low iodine. She told me to retest my thyroid hormones and iodine in 4-6 weeks.

Do you think it would be ok if I go to test my levels on 4th weeks or I have to wait six weeks to retest my thyroid hormones and iodine level?

Thank You!

P.S My previous lab results:

TSH 0.01 (0.40-4.50 mIU/L)

T3 REVERSE 13 (8-25 ng/dL)

FT3 3 (2.3-4.2 pg/mL)

FT4 0.8 (0.8-1.8 ng/dL)

IODINE, SERUM/PLASMA 44 (52-109 mcg/L)

FERITTIN 89 (10-154 ng/mL)

SERUM IRON 118 (40-190 mcg/dL)

SATURATION% 48 (11-50 % (calc))

TIBC 286 (250-450 mcg/dL (calc))

Thyroglobulin Antibodies 1 (< or = 1 IU/mL)

Thyroid Peroxidase Antibodies 2 (<9 IU/mL)

23 Replies

cant answer but how refreshing for gp giving ndt are you in uk

I am in the U.S.

Hi, I'm not a expert but I don't think you should mix the two together your free T4 maybe lower because ndt has T3 in so you body is not calling for more T4 , do you have ranges and results, also all vitamins & iron need to be optimal for the body to covert your ndt, some Drs add T3 to help, but you really need your results for anyone to really comment.

Thanks for your reply. I added my lab results. My folate and B12 were normal.

If your Dr knew anything about the thyroid and treatment they would know that when you take NDT that your T4 is suppressed. This is normal.

Thanks for your reply. I added my previous lab results. How about my FT3?

It's a bit low, you could add another grain or half a grain and ditch the T4. That's what I would do.X

You mean I can stop taking Levo and add another grain? or 2 grain+ 25 mcg Levo+ another grain?

Personally I would stop the levo. T4 is always suppressed when you take NDT.

I wouldn't take both.

From a purely absorption point of view, rather than if it was right to add levo, it takes 6 weeks for the body to fully absorb t4 so tests shouldn't e done at less of an interval than that. As to iodine, I don't know about that.

We really, really need to see the results and ranges of the tests to understand any of this. For example, how low was your iodine? Does your doctor know that taking 2 grains of NDT plus 25 mcg T4 will give you 65 mcg iodine, anyway? And, the last thing you want to do is over-dose on iodine. How does she test it? Is it a reliable test? Because most of them aren't. Do you have Hashi's?

But, in answer to your question, no, 4 weeks is not long enough. You need to wait the full 6 weeks.

Thanks for your reply. I added my previous lab results.

Not sure if iodine test is reliable or not. It was a blood test not urine.

I don't have Hashi's. My anti bodies came back normal.

She has ordered sex hormone test as well. If I go for blood test on 4th week, it would be 23rd day of my cycle. But on 6th weeks it would be day 9 of my next cycle. Don't know day 9 will give me a reliable results for my sex hormone test.

I don't think a serum iodine test is terribly reliable, no. But, given the level of iodine you are getting from your thyroid hormone replacement, I do not think prescribing iodine was appropriate. You do not want excess iodine.

A lot of doctors go crazy trying to increase the level of FT4 without realising that it is normal for it to be low when you are taking NDT. The body just keeps what it needs, and it doesn't need a high level of FT4. Does your doctor have much experience of prescribing NDT, or is she just used to T4 only?

Your FT3 is not quite mid-range, most people need it up the top of the range to feel well. But, it is very much down to how you feel.

If it were me, I wouldn't be happy with that TPO test. There's not much room for manoeuvre in that range, is there? Besides, antibodies fluctuate, so one negative test cannot completely rule out Hashi's. Try and get them done again in a few months.

You say your folate and B12 were 'normal'. In whose opinion? Doctors' opinions on the subject are often very wrong. Do you have the actual numbers?

I'm afraid I don't know anything about testing sex hormones, but I don't see why they all have to be done together. Why can't you have the sex hormones done on the right day, and the others in six weeks?

Don't know about her NTD experience. I found her name on Nature-Throid facebook page.

Do you think I should stop taking iodine?

I will definitely retest my antibodies in a few months.

My Folate Serum was >24 (>5.4 ng/mL)

and my B12 was 700 (200-1100 pg/mL)

Don't you think it will be better if I ask her to add 1 grain instead of 25 mcg Levo to bring up my FT3 and continue taking iodine? So, I won't be concerned about excess iodine. My hair loss has got worse since adding Levo.

I cannot tell you what to do. But, let's just say I wouldn't take it.

I think you would definitely be better off with another grain of NDT - although not added all in one go - rather than the 25 mcg T4. It would bring your FT3 up, which is rather low. But, it wouldn't change anything with the iodine. If anything, you'd be getting more iodine that way.

Having low Free T4 isn't a big issue, as long as you have enough Free T3 to keep you feeling well.

I take T3 only. I still have a thyroid which functions a little bit. When my Free T4 is tested it comes out at about 2 with a reference range of 12 - 22. However, both my Free T3 and my TSH are in range.

If adding Levo to your Nature-Throid makes you feel better than you do without it then there isn't a problem. But you may have been better off being prescribed a bit more Nature-Throid to help increase your Free T3 level.

As a marker of feelings of "wellness" Free T3 is a far superior indicator to TSH or Free T4 levels.

Thanks for your reply. I feel slightly better, but after adding Levo, my hair is shedding like crazy. I had hair fall but it's got worse.

Do you think stopping Levo and adding more NTD will bring up my FT4 beside my FT3?

I can only guess and make suggestions of what might happen. I am assuming you still have a thyroid which has some ability to produce T4.

If you had increased your Nature-Throid dose from 2 to 2.5 grains (and not taken Levo) it would depend on how you reacted to the extra bit of T3 you were getting. Your body may have decreased its own output of T4 because it knew you needed less due to the higher levels of T3. Your Free T4 may have barely changed, or it may have increased because, let's face it, NDT is mostly T4.

Taking extra NDT would possibly have increased your Free T3 slightly because it contains ready-made T3. But if your body reduced conversion from T4 to T3 there may have been little difference.

As you can see, there are so many ifs, buts, and maybes that it is impossible to tell you what would have happened.

All I can say is that some people do very well with very little T4 indeed. Some do very badly. You can only find out which kind of person you are by experimenting and finding out.

I think I have to wait for my blood test and see what my levels would be.

But if my levels, FT3 and FT4, come back normal, how much Nature-Throid should I add instead of 25 mcg Levo? Half a grain or 1 grain?

Guessing is really a pointless exercise! Wait until you have some real results, post them, and ask for feedback.

I'm on 2 grains of WP Thyroid, by the makers of Naturethroid, and wondering if your test results are using the trough method. Mean no thyroid medication the day of testing and you test when you would have taken your medication typically.

I did not my medication on day of testing.

Doctors don't seem to realise that taking any for m of T3 you read the results differently and only the FT3 result is accurate. So your FT3 needs to be high in the range but not. E over the range. FT 4 can fall to halfway as it doesn't have to store much if FT 3 is giving you what you need and TSH will be very suppressed and can be zero. So I would be adding extraT4 but concentrate on raising FT3

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