Dr John - Free Testosterone reference ranges

jaydee

Member
A guy on another forum pointed out to me that my labs were showing the wrong Free Testosterone ranges. For instance, the reference ranges on my blood tests for free T are 60 - 130 pmol/L. Yet guys who are getting their reference ranges in pg/mL, have reference ranges of 47 - 244 pg/mL.

When you convert the pg/mL to pmol/L, you get a reference range of 163 - 846 pmol/L. That is a huge difference and would mean that even though my labs say I am OVER my range, I could be in fact under the correct reference range.

Is this correct?
 
jaydee said:
A guy on another forum pointed out to me that my labs were showing the wrong Free Testosterone ranges. For instance, the reference ranges on my blood tests for free T are 60 - 130 pmol/L. Yet guys who are getting their reference ranges in pg/mL, have reference ranges of 47 - 244 pg/mL.

When you convert the pg/mL to pmol/L, you get a reference range of 163 - 846 pmol/L. That is a huge difference and would mean that even though my labs say I am OVER my range, I could be in fact under the correct reference range.

Is this correct?
Click to expand...

Thre are many useless Free Testosterone tests.
Read more here:
Invalid Link Removed
Quote "I know of no other that has been demonstrated
to be so egregiously incorrect."

I am trying to spread the news since I found obout it few moths ago.

There is workaroud, get TotalT, SHBG and Albumin in the same blood draw and calculate your self using:
Invalid Link Removed
and
Invalid Link Removed

Only Quest Diagnostic have correct FreeT, but it also makes it hard to get. On standard ordering form they list the bad one. To get correct one you have to order
Free, Bioavailable, and Total Testosterone.
Invalid Link Removed

When Dr Shippen is adjusting its patients and try a range 100-250 that is for the correct FreeT.

There is 2006 work that discusses better method of calculating to account for new knowledge about SHBG.
-----http://www.atypon-link.com/WDG/doi/pdf/10.1515/JLM.2006.050

It does not help me much, but it have information of FreeT and BAT levels in healthy men,
Table2
10 healthy young men BAT=5.5(nmol/L)
Table 4
10 male control subjects FreeT=199(pmol/L)
=======================
Please add to this topic.
 
JanSz said:
Thre are many useless Free Testosterone tests.
Read more here:
Invalid Link Removed
Quote "I know of no other that has been demonstrated
to be so egregiously incorrect."

I am trying to spread the news since I found obout it few moths ago.

There is workaroud, get TotalT, SHBG and Albumin in the same blood draw and calculate your self using:
Invalid Link Removed
and
Invalid Link Removed

Only Quest Diagnostic have correct FreeT, but it also makes it hard to get. On standard ordering form they list the bad one. To get correct one you have to order
Free, Bioavailable, and Total Testosterone.
Invalid Link Removed

When Dr Shippen is adjusting its patients and try a range 100-250 that is for the correct FreeT.

There is 2006 work that discusses better method of calculating to account for new knowledge about SHBG.
-----http://www.atypon-link.com/WDG/doi/pdf/10.1515/JLM.2006.050

It does not help me much, but it have information of FreeT and BAT levels in healthy men,
Table2
10 healthy young men BAT=5.5(nmol/L)
Table 4
10 male control subjects FreeT=199(pmol/L)
=======================
Please add to this topic.
Click to expand...

No wonder it gets confusing. One of the websites have 3 tables and I can't decypher exactly what the normal values are!
 
SoMdHunter said:
No wonder it gets confusing. One of the websites have 3 tables and I can't decypher exactly what the normal values are!
Click to expand...

Quest Diagnostics shows ranges for their tests here:
Invalid Link Removed

The Total T column and the two right columns are to be used.
 
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