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Free Testosterone Direct vs Dialysis

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)


That looks right. Usually results in pg/mL are in the 100’s

The Direct Immunoassay is worthless, the Equilibrium Dialysis or Ultrafiltration are the most accurate. Sadly these latter two testing methods aren’t available in other countries outside the US.