Aa
A
A
A
Close
Thyroid Disorders Community
26k Members
1139187 tn?1355710247

Question about t4 only treatment

I know everyone is different, but lets say that I am the "average" thyroid patient on t4 only.  I know that most people feel better when the ft3 and ft4 is in mid to high range, but what does a normal person's labs look like?   Lets say someone who doesn't have thyroid disease?   I am trying to figure out where i am trying to land, especially with the ft4.  I realize the ft3 can be adjusted up, but the ft4 is what I'm curious about.   lets say these are the ranges

tsh .45- 4.5    (i am aiming for 2.0)  a friend of mine does not have thyroid disease, his is 1.54
free t4   .9 to 1.9    (what is a normal person's ft4?)
free t3   2.3 to 3.9   (realistically Id like to be 3.5 or so)

My main questions again - what does a normal person with no thyroid disease have ft4 wise, and what is a realistic goal?
26 Responses
1756321 tn?1547098925
"A study of euthyroid adult population was undertaken to determine expected values for the Free T4 EIA Test System.  The mean (X) values, standard deviations (σ) and expected ranges (±2 σ) are presented in Table 1.

TABLE I

Expected Values for the Free T4 EIA Test System
(in ng/dl)

Adult (89 specimens)  
Mean (X) 1.40  
Standard Deviation (σ)  0.30  
Expected Ranges (±2 σ) 0.8 – 2.0

Pregnancy (3 Ispecimens)
Mean (X) 1.50
Standard Deviation (σ)  0.37
Expected Ranges (±2 σ) 0.76 – 2.24"

Excerpt from Diagnostic Automation Inc - Free T4 ELISA kit  

***

"A study of euthyroid adult population was undertaken to determine expected values for the FT3 DAI ELISA test system. The mean values (X), standards deviations (σ) and expected ranges (±2σ.) are presented in Table 1

TABLE 1

Expected Values for the Free T3 ELISA Test System  
(in pg/ml)

Adult (110 speciments)  
Mean (X) 2.8
Standard Deviation (σ) 0.7
Expected Ranges (±2 σ) 1.4 - 4.2

Pregnancy (75 specimens)
Mean (X) 3.0
Standard Deviation (σ)  0.6
Expected Ranges (±2 σ) 1.8 - 4.2"

Excerpt from Diagnostic Automation Inc - Free T3 ELISA
1756321 tn?1547098925
"When we have a normal population data for serum TSH we need to log-tranform the values in order to get the familiar bell-shaped curve that defines a normal distribution. The normal range is usually quoted as about 0.4 - 4mU/L (millunits per litre), but the log transformation introduces one peculiarity - it move the mean and median values for TSH down towards the lower end of the range - at about 1mU/L.

The upwards tail between 2 and 4mU/L is rather thin, and there is room for doubt as to whether values in this range are actually normal or not. The important point is that when normalizing TSH by treatment, our target (the mean and median) TSH value should generally be around 1mU/L. If we simply aim for TSH in the middle of the range, some individuals will remain under-treated."

- Prof Jim Stockigt. "Subclinical hypothyroidism or Mild thyroid failure: How important is early diagnosis and what treatment is optimal? Sigma Pharmaceuticals, March 2001. [Thyroid Australia, Thyroid flyer. 2:3, July 2001.]
649848 tn?1534637300
COMMUNITY LEADER
Thyroid levels in people who do not have a thyroid condition, have hormones "on demand", meaning that their thyroid produces, or they convert, to produce adequate hormones, as needed, which fluctuates throughout the day.  

Those of us who have a thyroid condition and are on replacement medication, do not have the hormones on demand and must rely on adequate dosage/conversion in order to keep our levels where we need them.

It's already been shown that people with undiagnosed thyroid conditions, help make up the basis for the so-called "normal" ranges, which causes them to be flawed.  The AACE recommended that the TSH range be adjusted to take this into consideration, but most labs, and therefore, doctors, don't go by the new range (0.3-3.0), which leaves many people with TSH above 3.0, undiagnosed.  Likewise, many people with lower levels of FT3 and FT4, could be undiagnosed as well, because those ranges have not adjusted.  

Bruce, you can't just target numbers, out of the clear blue sky, because they sound good or because someone else had numbers like that...... you'll know you're where you need to be, when your symptoms are gone.  Just because one person feels good with an FT3 at 3.5, doesn't mean that's the number you should target.  I, personally, felt best at 3.7, but that may be too much or too little for someone else.  Additionally, I didn't pick that number arbitrarily -- it came up on labs, when I felt best and when my level dropped, I didn't feel well.  
Avatar universal
I agree with Barb.  She and I could be the poster children for the upper and lower ends of the ranges.  My last FT3 was 2.5, and I feel great.  You just have to find your own personal space.

I also agree about the hormones on demand.  Since we no longer have that, I think once on meds, where we need to be changes quite a bit.  We have to run hormones high enough to cover peak demand periods, and as a result, we probably have to be a little higher in the ranges than the "normal" population.

"tsh .45- 4.5    (i am aiming for 2.0)  a friend of mine does not have thyroid disease, his is 1.54"  You really can't aim for a number, but if you insist, please aim at something other than TSH.  You've heard us talk about the limitations of TSH...really, it's totally irrelevant.  You'd be much better off setting your sights on FT3...don't get me wrong, you still can't pick a number out of the air and shoot for it, but it's your FT3 level that will ultimately control how you feel more than any of the other tests.
Avatar universal
Everyone is different. ...

Hard to tell...
1139187 tn?1355710247
Being a man with a woman's disease can be quite difficult at times.   Y'all all answered the question, but no one answered my question.  LOL

all i am asking is -  in a normal every day human being, what is their t4 level.  If you took 100 people and they all had healthy thyroids,  and tested them, what would their t4 levels be?

this is more of a curiosity question that a co-roid and i were having as part of a discussion the other day.  

Im just really interested in the ft4.  I know barb and mrs. goolarra have higher tsh's but I'm just curious.
Avatar universal
Well, look on the bright side...at least you're not pregnant!  

Theoretically, if you take 100 healthy people and test their FT4 levels, you are going to get the old bell-shaped curve of results.  Of course, with 100 people, you will not get this nice distribution, but with 100,000, you will.

Ready for some math?  Pay attention, becuase there WILL be a quiz.

So, let's us Red_Star's statistics:

Expected Values for the Free T4 EIA Test System
(in ng/dl)

Adult (89 specimens)  
Mean (X) 1.40  
Standard Deviation (σ)  0.30  
Expected Ranges (±2 σ) 0.8 – 2.0

Of those 100 people, we would expect approximately 68 to be within one standard deviation of the mean, i.e. 68 would fall between 1.1 and 1.7.  Another approximately 14 would be between 0.8 and 1.1, and another 14 between 1.7 and 2.0.  The remaining 4 would be in the upper and lower tails of the curve, i.e. "abnormal".

You're confusing your ladies again...not nice...Barb has very LOW TSH , and I have very HIGH TSH.  Try to keep us straight, please.  LOL
1139187 tn?1355710247
damn that was a very confusing post.   Posts like that should not be allowed in this forum.  People with hashimotos do not have the healthy mental capacity to figure out formulas like you just posted.

What were we talking about again?

Ok so the answer is, it could be all over the place.  There is no standard answer or common number for the general population.  

Wherever you got those numbers from its interesting that 14 of them (those poor souls)  are .8 to 1.1.   I wonder why they are borderline hypo but are normal.

A friend of mine who cuts my hair has a genetic liver disease.   Ive known him my whole adult life and his eyes are always yellow.  They are putting him on something now and ran all his labs.  He showed them to me and his gastro ran his TSH and ft4.    His tsh was 1.54   Range .45 -4.5     and i cant remember his ft4 but it was very nice  and i hate him for it.

But then i started talking to another hashimotos person and we were discussing how she was on armour and i was now on t4 only and we got in this whole discussion about where i would end up when finally optimized.   So there ya have it...

Avatar universal
"Ok so the answer is, it could be all over the place.  There is no standard answer or common number for the general population."

Praise the Lord and pass the ammunition...I think you've got it!!!

"Wherever you got those numbers from its interesting that 14 of them (those poor souls)  are .8 to 1.1.   I wonder why they are borderline hypo but are normal."

Hey, don't forget that I'm one of those "poor souls".  In fact my FT4 was just a tad below range last time I had labs, and I feel just fine.  People like me don't usually end up on forums because once our doctors get us into range, we're happy as pigs in poop (or maybe even just a little hyper).

So, yeah, there you have it...it's all over the place, which is why we all have to find our own sweet spot.  You'll know it when you find it...

1139187 tn?1355710247
but wait,  i thought you were telling me about people with NORMAL thyroids.   your thyroid is far from normal LOL   your thyroid has been run over backwards by the hashimotos express.


where are those numbers from?   the staff of medhelp?
Avatar universal
No, the numbers come from the stuff that Red_star posted:

"Expected Values for the Free T4 EIA Test System
(in ng/dl)

Adult (89 specimens)  
Mean (X) 1.40  
Standard Deviation (σ)  0.30  
Expected Ranges (±2 σ) 0.8 – 2.0 "

The mean is 1.40, and the SD (standard deviation) is 0.30.  With a bell-shaped (normal) curve, 68% of the results will be within one SD either side of the mean.  (1.4 - 0.3 = 1.1, and 1.4 + 0.3 - 1.7).  14% falls into the next SD on either side of the mean.  It's all math...statistics really.

Yes, my thyroid has been run over, BUT I still feel good where I'm at, and that's all that matters.

1139187 tn?1355710247
Ok i retract my comment a couple posts up.   My question remains open.

I will google it, and maybe Gimel will chime in, but I'm just curious to know if there is a scientific study or basically what you guys think most normal folks thyroids are at that do not have any of the stuff we have going on  (free t4).

I know the Tsh's because a couple of my friends have shown me labs but I'm curious to know what normal t4's look like.

ALso we know its hard to get a nice healthy high ft4 with nth,  but what is a nice healthy ft4 on t4 only.

LOL   oh, and in laymen's terms.
Avatar universal
You guys are having so much fun with this that I am somewhat reluctant to join the party.  However, I will say that taking into account that the ranges that we see most often are different from the ones Red posted, and also based on some training and background in statistical analysis, I have previously estimated that if the range for Free T4 were adjusted similar to that done for TSH prrviously, the new range would be more like 1.0 - 1.55.  Similarly, if the data base for Free T3 were purged of suspect hypo patients, the new range would be more like 3.2 - 4.3.

In addition I learned about an instance where a lab was questioned about their range for Free T4, at .60 - 1.50.  They acknowledged that it was based on all patient data.  When asked to give a range for patients with no known hypo problems they replied that it would be about 1.0 - 1.50.

Also I have seen several sites that talked about a functional range for Free T3 being the upper half of the current range.

Anyway, ranges should be nothing more than guidelines within which to adjust Free T3 and Free T4 as necessary to relieve symptoms.

I don't know that you need a "nice healthy high FT4".  Free T3 is the critical level to watch, along with symptoms.  While taking 200 mcg of T4 I had a FT4 that was slightly over the range but still had lingering hypo symptoms, until I learned about FT3 and got my meds switched to NDT.   On 3 grains of Armour my FT3 was 3.9, and my FT4 was .84, and I felt great.  Now I have added 25 mcg of T4  just to get FT4 to around the midpoint at 1.14.
1756321 tn?1547098925
From the information i posted above, the mean (average) test results found in euthyroid (normal thyroid function) patients [not pregnant] - FT4: 1.4ng/dL, FT3: 2.8pg/mL. The TSH: 1mU/L.  The standard deviation of the FT4 is 0.3pg/mL which means plus or minus 1.4ng/dL (down to 1.1ng/dL or up to 1.7ng/dL).

This may not be what you feel best at, but it does answer your main question, based on one study, "what does a normal person with no thyroid disease have ft4 wise".  What average lab ranges for optimally treated thyroid patients is another matter. I highly doubt that has been studied. Maybe a poll question? :)
1756321 tn?1547098925
I meant the standard deviation of the FT4 is 0.3ng/dL not pg/mL. Too many lab measurements going around. :P
1139187 tn?1355710247
Thank you .    Gimel -  I felt bad with a ugh ranger ft3 but lower ft4.  SO the doctor decided to put me on ft4 only and will adjust the t3 if needed.  But In my mind i was still trying to think about where i would like to end up even though at this rate I'm far from it.

Red star-  those were some serious statistics.   After reading your post above (the first paragraph) about 12 times, I think i finally figured out what you meant LOL   My hashimotos brain could not really comprehend it, but i took a nap, ate lunch and came back and re-read what you said.

Barb and Goolarra -  Thank you for making me realize that I am not actually the most un - normal thyroid patient on here  LOL
1756321 tn?1547098925
LOL oh dear...that naughty hashi brain. :)
1139187 tn?1355710247
Yeah.   There should be a warning label on this thread.  
649848 tn?1534637300
COMMUNITY LEADER
"Being a man with a woman's disease can be quite difficult at times."

While it's true that hypothyroidism occurs most often in women, it should NEVER be considered a "woman's disease", because everyone has a thyroid and the potential for problems exists in us all.

There's nothing abnormal about your thyroid condition; your biggest problem has been impatience and listening to too many different people, all at the same time.
1139187 tn?1355710247
so bummed today.  met a lady at the grocery who has been taking 275 of synthroid for 17 years.  she says she is so tired she has to go home and nap every day after work.   17 years!!!  and shes exhausted!
1139187 tn?1355710247
She also said after 1 pm today she can hardly function.   I wonder if her ears ring 24 hours a day and she feels like shes on a rocking boat
1139187 tn?1355710247
I wonder if the ringing will ever get better.  I have a small theory that one day my blood will be saturated with the right amount of hormone and every time i take a dose, it will just be a drop in the bucket.  But right now it literally hits me like a sledgehammer every time i take a dose.
Avatar universal
And did you invite that lady to join us on the Forum so that she might be able to find out what is causing her to still be so tired, even with taking 275 mcg of T4?  LOL
1139187 tn?1355710247
no but she was writing the information down like i was telling her the secret of the universe.

I showed her my cell phone that had all my quest lab quests on it (the gazelle app from quest)  and you would of thought i just told her who really shot kennedy.
Have an Answer?
Top Thyroid Answerers
649848 tn?1534637300
FL
Avatar universal
MI
1756321 tn?1547098925
Queensland, Australia
Learn About Top Answerers
Didn't find the answer you were looking for?
Ask a question
Popular Resources
We tapped the CDC for information on what you need to know about radiation exposure
Endocrinologist Mark Lupo, MD, answers 10 questions about thyroid disorders and how to treat them
A list of national and international resources and hotlines to help connect you to needed health and medical services.
Here’s how your baby’s growing in your body each week.
These common ADD/ADHD myths could already be hurting your child
This article will tell you more about strength training at home, giving you some options that require little to no equipment.