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Thyroid Disorders Community
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Avatar universal

need help interpreting hypo lab results

I was diagnosed hypo a few months ago.  Symptoms are mostly major fatigue, muscle weakness, cold feet.

My initial labs were as follows:
TSH: 1.21 (range is 0.20-4)
Free T4 is 11.3.  (10.0-25.0 pmol/L)
Free T3 is 3.3.  (3.5 - 6.5)
Thyroid Peroxidase antibody is 13 (0-34)

I was put on a small dose of synthroid.  Started at 25 mcg.  Moved to 50 after two weeks.  Tested at 4 weeks.  (The 50 mcg made me feel awful...hypo and hyper symptoms and major headache.)

Results after four weeks on a very low dose of synthroid:

TSH 0.72 (0.20 - 4.00 mIU/L)
- FREE T4 17.2 (10.0 - 25.0 pmol/L)
- FREE T3 3.8 (3.5 - 6.5 pmol/L)

Because I wasn't reacting well to the synthroid, I asked my doctor for ERFA thyroid.  

So far, I have felt more tired and my temps were lower than usual for a while on it (they are finally coming back up).

I started on 15 mg for one week, then took 30 mg for three weeks (that's half a grain I believe).  Just got blood work done after one month (to be semi-consistent).

Results:

TSH: 1.1 (range is 0.20-4)
Free T4 is 11.9.  (10.0-25.0 pmol/L)
Free T3 is 3.5.  (3.5 - 6.5)

Now I'm really confused!  It looks like I was doing much better on the T4 only even though I wasn't feeling good.  (I know that's a tiny dose but I am generally very, very sensitive to medications and supplements).

I have been taking B vitamins and D3.  I also got my ferritin tested this last time and the result was low: 63 13 - 375 ug/L.

I would love anyone's thoughts on what these numbers mean.  I feel like I am finally over the hump with ERFA (it's been a struggle with my other hormones and my temp is finally normal-ish and I finally ovulated...sorry if that's too much information).  

Any help?  Advice?  Thank you so much.


7 Responses
Avatar universal
It looks like you need an increase.  FT4 is very low at 13% of range.  Many of us found that FT4 had to be around 50% of range before symptoms were relieved.  As you can see, FT3 is right at the bottom of the range, far below the upper half to upper third of range that is the target here.  TSH is flat out "normal", which indicates your pituitary is happy with your levels.  That could point to secondary hypothyroidism, which is actually a pituitary malfunction...the pituitary doesn't put out enough TSH to stimulate the thyroid to produce enough.  

Like you, I am ultra-sensitive to all meds.  Over the years, I have learned that I have to increase very slowly and really give my body time to get used to every dose change.  Typically, dose changes are in increments of 12.5-25 mcg, but that's way too fast for me.  I'll get hyper-like symptoms on that kind of increase.  I've finally discovered that what I have to do is increase about 3 mcg a day, do that for a month or so, add in another 3 mcg, etc. and then the increase is seamless.  

Do you split your dose into two half doses?  
Avatar universal
Thank you so much goolarra.

I do split my dose.

I agree that I need to increase.  I suppose I am just confused about why my numbers seemed to be much more responsive on the synthroid than the Thyroid. I wonder if that means synthroid is actually better for me (even though it messed up my ovulation/menstrual cycle and gave me bad headaches and forgetfulness).

I also figured I would be just as sensitive to the erfa thyroid as the synthroid but it doesn't seem to be the case.

Finally, if I do have secondary hypothyroidism, is the treatment the same?  

I really appreciate the help.  If you have another moment, I would love your thoughts again.
Avatar universal
Your body ONLY uses the T3 at the cellular level. So if you look at your FT3 levels on both Synthyroid and the ERFA they are almost identical.  Which are at or towards the very bottom of the range. ANd most people seem to feel well with this at the 50% if not up to the 66% of the range.

The best you have tested for FT3 is 3.8 which equates to only 10% of the range.

On a natrual dessicated thyroid NDT like ERFA it is common to be low in the range if not even below range in FT4 while the FT3 can be better since NDT has a large portion of T3 in it.

Yes it is important to split doses of NDT or when taking any significant dose of T3.

I personally just think you need to be more patient and give the ERFA more time.  But I think you should talk to your Dr about a bump up in dosage.

Also do NOT be surprised if you up you dosage of ERFA that the TSH suppresses. It can happen very fast and it is a reactio to the medicine and is NOT necessarily mean that you are Hyper.  So do NOT let the Dr get freaked out if or when that happens. You are only Hyper if you have the symptoms to go along with and be consistent with being hyper.

That all said if you want to switch back to T4 only medication that is up to you.  But understand that hormones are tricky and finicky things.  And it takes a LONG time to really settle out.  So you don't want to make too many changes too often.  Slow and steady, until it is clear the course you are on is not taking you where you want to go.  I don't think in only two months you have determined this yet.  Many here have taken YEARS to get optimized dose.
Avatar universal
I really appreciate this advice.  I have been reading so much but forgot that T4 doesn't really matter when on NDT.  Thanks again.

One more question: I am splitting the dose but still confused about how it should be taken: swallowed or sublingually?  And is it ok to take it near food?  I keep trying to find the answers to this one and keep coming up with more questions.
231441 tn?1333892766
Hi,

the main thing with thyroid meds is to take them consistently the same way every day.

Better to take it away from food, if you can.  Swallowed or subligual - whatever works for you.  I can't get it my erfa to dissolve enough to do it sublinqual and to me it tastes like something dead (it is!), so I just swallow it.

Be patient.  I'd also say stick with the erfa but increase the dose slowly.  Don't worry about TSH any more.  From now on, FT3 and FT4 are the parameters that guide your treatment (and how you feel).
Avatar universal
You really weren't on Synthroid long enough for the dose to even settle.  It takes 4-6 weeks before a dosage reaches its full potential in your blood.  

You're on a low dose of Erfa.  It takes time.  I agree with Sally; I'd give it more of a chance.  

Okay, so you have been diagnosed with secondary.  That means TSH is totally meaningless.  All hypo, regardless of cause, is currently treated the same.  There's no way to treat anything, except to replace the hormones the thyroid can no longer make.  After surgery, RAI, when Hashi's has destroyed it, if you have secondary, we're all in the same boat.  
Avatar universal
Being on NDT does not make FT4 meaningless.  However it is common for it to be low in the range.  And your body only uses FT3 at the cellular level.

That in no way means that FT4 levels are not important.  While you might feel pretty well with low FT4 and the FT3 levels where you need to be in an OK point for thyroid level to feel well.

However then you are essentially "living" on the oral FT3.  And I would argue that it still is a good idea to have an FT4 level that is about mid-range (50%) as it is a storage hormone. And in certain times your body would ahve th FT4 available to be converted if it needed to.  Especially if you happen to forget a dose or two of the NDT from time to time or there is some other "emergency" that your body finds the need to have FT3.  And it can then go to the FT4 reserves to convert it IF it needs it.

Also I have read at least one thing once were FT4 and how it breaks down if not used for conversion goes into soem sort of an enzyme that helps pervent tumors in your body. And the ONLY way that this chemical is made is from T4.  So if this is true, it is another reason to have a fair amount of FT4 level even if that means adding back in a dose of T4 medication IN ADDITION to the NDT dose.  

My wife is on Armour only currently and while she is getting I think close to optimized on FT3, her FT4 levels are very low.  So I think she is also in the position where it may make sense for her to add in T4 medication in addition to her Armour.

Also while some people can feel perfectly symptom free with NDT and good levels of FT3 and low levels of FT4.  Other people do not, and they need to have a reasonable balance of both FT3 and FT4.

Everyone is a little different.
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