Question about Free Testosterone tests

[Arcane]

My Dr typically orders the Free Testosterone (Direct Test), which Ive been told is inaccurate. I was prescribed 100 mg Every 3.5 days and my reading was:

Free Testosterone(Direct) = 28.3 pg/mL (9.3-26.5).

so slightly high.

After posting on here, I was informed that Dialasys test was much more accurate and the gold standard for Free testosterone readings.

My protocol has changed to a more frequent dosing administration: 25 mg EOD, and I just got my bloodwork back:

Testosterone, Free (Dialysis) = 153.1 (35.0-155.0 pg/mL)

Can Someone explain to me why my Free T is in the 100s? Is the dialysis measurement read differently even though it uses the same unit of measurement? (pg/mL)

 

[madman]

My Dr typically orders the Free Testosterone (Direct Test), which Ive been told is inaccurate. I was prescribed 100 mg Every 3.5 days and my reading was:

Free Testosterone(Direct) = 28.3 pg/mL (9.3-26.5).

so slightly high.


After posting on here, I was informed that Dialasys test was much more accurate and the gold standard for Free testosterone readings.

My protocol has changed to a more frequent dosing administration: 25 mg EOD, and I just got my bloodwork back:

Testosterone, Free (Dialysis) = 153.1 (35.0-155.0 pg/mL)

Can Someone explain to me why my Free T is in the 100s? Is the dialysis measurement read differently even though it uses the same unit of measurement? (pg/mL)
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Again the direct immunoassay is known to be inaccurate and as I stated you would need to have your FT tested using the most accurate assays such as the gold standard Equilibrium Dialysis or Ultrafiltration (next best) to know where it truly sits.

Your FT level on a whopping 200 mg/week T (100 mg every 3.5 days) using the direct immunoassay came back slightly over and I would have bet that it would have been a lot higher if you had it tested using an accurate assay.

Luckily you had it retested using an accurate assay but your T dose was cut down significantly as you are now on a 25 mg T EOD and as you can clearly see your FT is still on the high end.

*If you were still on the whopping 200 mg T (100 mg every 3.5 days) protocol and had your FT tested using an accurate assay it would have been through the roof!


Unfortunately, when it comes to the reference ranges for measured or calculated FT they vary between different labs, and as of now, there is no standardization let alone a harmonized reference range.

Efforts are underway to standardize the procedures for FT and to generate harmonized reference ranges.

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