T Nation

Free T Determination


Need help in determining free T . I am a diabetic so my lab tests are ordered by my Endocrinologist. I also have ED as a consequence of the diabetes. I noticed last year that my total T was ranging between high 200s and low 300s but my Endo considered the level acceptable for some one approaching 70. However, Inwanted to try TRT in hopes it would improve my ED. I visited a urologist who prescribed 1% Testim gel in June which has considerably improved my libido, but, unfortunately, had little effect on my ED

Earlier this month my Endo ordered a lab test and at my request included tests for T. I have the test results which were satisfactory for my Endo, but I do not have an appointment with my Uro for another two months to discuss the T results and was hoping I could get some help here. It is a three page report so I will list some of the more relevant results.

PSA 1.31 ng/ml (0 to 4)
LH 0.1 miu/ml. - low (.8 to 6.1)
FSH. 0.6. Miu/ml. - low (1.6 to 11.0)
Cortisol. 14.9. Ng/dl
Estradiol. 47. Pg/ml. - high (10 to 45.0)
Testosterone 765. Ng/dl ( 241 to 827)
TSH 2.4. Uiu/ml (.27 to 4.2)
Free T3 3.4 pg/ml
Free T4. 1.5. Ng/dl
Total T3. 130 ng/dl
SHBG. 73.8. Nmol/L. - high (7 to 50)

I did not notice a result labeled Free T and was wondering if any of the above represent "Free T" or can be used in calculating FreeT? Any other comments would be appreciated as well.


None of the listed results can help pin down Free T. The only thing we can really determine is that your estrogen is probably on the high side. This will lower your Free T even in the presence of good Total T.

Use the function to go back and add units and ranges to your labwork--they vary by lab and its hard to keep them straight otherwise.

To calculate your Free T, you will need SHBG. Some labs will also do Free T as a serum assay as well as calculating it.


Thanks for the reply. I found the SHGB results - 73.8. nmol/L and included them in my original post plus units of the results.


not units... lab ranges... helps us determine the type of test and they match up to what ranges we expect.


Ranges have been added to test results. Can free T be determined approximately using total T and SHGB?


I have no idea how accurate this site is - I just did a simple google search for 'determine Free T with Total T and SHBG' and I came across this site.


Your TSH is high, but your free T3 numbers look pretty good (if the test range is around 2.0-4.4).

people with thyroid issues seem to have issues absorbing medicated gels/creams.


Thanks for the link, PureC. I entered my test results and it calculated my free T to be 9.53 = 1.25%. Seems like a reliable web site. I have saved the address and will use it in the future to track my Free T..

Thanks again for your effort and help.. I am new to this so I am still at the beginning of the learning curve..


it takes awhile. I have been diving deep into this stuff for three years now and only understand a small portion of it.