What is T3 Uptake?

[CROM]

Can anyone tell me what T3 uptake means? I took a TSH test and it was 5.20. I then took a complete TSH test a week later and my numbers are as follows:

Free T4 Index (T7) 2.7 - Range 1.4-3.8
T4, Free 1.4 - Range 0.8-1.8
T4 (Thyroxine), Total 7.2 - Range 4.5-12.2
T3, Total 97 - Range 76-181
T3, Free 3.6 - Range 2.3-4.2
T3 Uptake 37 - Range 22-35 High
TSH 5.44 - Range 0.40-4.50

Everything is within range except T3 uptake.



I don't know if this matters but I did full blood work cuz I want to qualify for testosterone injections. Everything in my blood work was normal except the following:

TSH 5.20 then a week later it was 5.44 - Range 0.450-4.500
Testosterone, serum 147 ng/dl - Range 264-916
LH 0.1 - Range mIU/ML - Range 1.7—8.6
SHBG 12.2 nmol/L - Range 16.5-55.9

Yes my testosterone is low. It has never been over 224 in last 10 years. I started Testosterone gel five months ago but that obviously is not going well.

I have read that synthetic testosterone can raise T3 Uptake. But I see others who have a normal T3 uptake while on TRT. Anyway, any ideas on my TSH? Will it prevent me from getting T injections? The only thing of my TSH that was out of range was T3 uptake.

Thanks for any help.

 

[Vince]

These assays have been variously referred to as T3-uptake, T4-uptake and thyroid-uptake tests, depending on the assay design. All are used in exactly the same manner and for the same purpose, not as stand-alone assays, but in combination with total T4 or total T3 assays. Matched T-uptake and total T4 results are used to calculate a free thyroxine index (FT4I or FT3I). The FT4I serves as an indirect estimate of free T4 levels, and were heavily relied upon historically, particularly before direct free T4 assays became available. The resin T3/T4 uptake is used to assess the binding capacity of the serum for thyroid hormone. This is used to help determine if the total T4 is reflecting the free T4, or if abnormalities in binding capacity are responsible for changes in T4 values and thus this test is only useful in conjunction with Total T4 or Total T3. In the Resin T3 Uptake test, labeled hormone is added to the patient's serum. If there is an increase in binding capacity, more labeled hormone will be bound to the binding proteins and thus less will be left free in the serum. The free labeled hormone in the serum is measured and usually reported as a percent of the total labeled hormone added. If a patient has a high total T4,


it may be due to overproduction of thyroid hormone (Hyperthyroidism) or to an excess of one of the thyroid binding proteins, usually thyroid binding globulin (TBG). If the high Total T4 is secondary to high TBG, the Resin T3 will be low, otherwise it will be normal or elevated. Another way of putting this is that if the Total T4 or Total T3 deviates from normal in one direction and the Resin T3 uptake deviates in the opposite direction, then the abnormality is due to changes in binding capacity, otherwise it is secondary to a true change in thyroid function (i.e. Hyper- or Hypothyroidism). For example, if the binding capacity is increased because of high estrogens, the free labeled hormone will be decreased and the Resin T3 uptake will be decreased.​

https://www.excelmale.com/forum/showthread.php?3184-Thyroid-Tests-and-What-They-Mean

 

[1Draw]

Your TSH is very high. 5.44 (.040-4.50)
Here is great resource for optimal ranges
https://www.restartmed.com/normal-thyroid-levels/

Your thyroid is out of whack big time. You need full recommended thyroid labs with Reverse T3.

 

[1Draw]

Also don’t worry over T3 Uptake. It has little value. Most important are T4, Free T3, RT3 and ratio. Here is more information on RT3.
https://stopthethyroidmadness.com/reverse-t3/

 

[CROM]

I have a doctors appointment on the 23rd. What other tests should I get before that appointment?

So I will get an RT3 test. But what else? Should I get a thyroid antibodies test or anything else? I want to have all my tests done before I see the doctor.

Also, do you need to take the T3 in the same blood test as RT3? Cuz I took the T3/T4 last week. I would hate to spend more money on test I already took If not needed.

Thanks.

 

[1Draw]

Nope you’ve got the most important T3, FT3 and the T4. Just missing the reverse T3. Check the ratio of T3 to RT3 and should be more than 20.

 

[CROM]

Thanks for your input sir. Gonna take this test at tomorrow.

 

[Nelson Vergel]

I have a doctors appointment on the 23rd. What other tests should I get before that appointment?

So I will get an RT3 test. But what else? Should I get a thyroid antibodies test or anything else? I want to have all my tests done before I see the doctor.

Also, do you need to take the T3 in the same blood test as RT3? Cuz I took the T3/T4 last week. I would hate to spend more money on test I already took If not needed.

Thanks.

Here is a comprehensive panel:

https://www.discountedlabs.com/thyroid-panel-comprehensive

Use this code: 5%OFFNOW (all caps)