T Nation

4 Wks After PCT, Free Test Levels vs Total

I just got my labs done, after 4 weeks of pct with Nolva

My total testosterone is 661.9 ng/dL ( ref range is 260-1000 )
Free test is shown as 27.79 pg/mL ( ref range is 15-50)

So If I convert my free test from pg/mL to ng/dL, I have only 2.77 free test out of 661?
Still wondering if 2.77 is a possibility ? and its not in RED color on my report/its in normal range, so just wondering

Is this LabCorp units? IIRC, they don’t have the correct units on FT (should be in ng/dL as well IIRC).

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Just look at where you fall inside the range, IMO. There’s debate on whether it’s actually a typo on the unit or a result of the method of measurement Labcorp is using, but, regardless, the range is designed around the test method, so they should align.

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Labcorp uses the wrong units. Should be ng/dL. Your value looks great

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Thank you for the reply everyone, it isn’t labcorp , just a local lab in my region.
I believe it should be ng/dL.
The Methodology written in the report is : Chemiluminescence Immunoassay Technique

Also I am being told that Free test levels are about 2% of Total Test levels, so (661x2% = 13), I have 2 times of 13x2 27? if it makes any sense ?

Don’t suppose they checked your SHBG?

If you want the gory details…there’s no “debate” here. There’s exactly 0% chance that Labcorp would continue to result out incorrect units on an FDA approved blood test if that was actually an issue.

In your particular case, you’ve had a variant “direct” RIA free Test measurement which typically varies by a factor of most typically 5 to 7 (the test variant is measuring a proxy for free Test and highly correlates with free Test, but the slope is not 1) vs a calibrated free Test calc or gold standard ED/LCMS free Test measurement.

The story that the units of the direct free testosterone assay (RIA) are reported incorrectly is myth.

Rough math… 13 / 2.77 = 4.8 ~ 5 ( all units in ng/dL).

If you have your SHBG, we can confirm your 2% free Test assumption.

** For the interested reader, take a look at the links above. It’s important that incorrect information doesn’t keep getting repeated so we can increase understanding and literacy in this field.**


That’s what I thought. I couldn’t remember if it was “off” by a factory of 5 or 7, guess it was more like 5. I’ll have to save your post this time for the next time this comes up.

No kidding … so it’s not really suppose to be ng/dL for Labcorp? It’s just off by a factor of 5?

Really important to have the reference ranges in this case.

Just out of curiosity, how many weeks after stopping Nolva did you do these labs?

just the next day of exact 4 weeks, 40/40/20/20 I wanted to do it for 6 weeks, but Injected 100mg test prop as soon as I got replies on my post.
& no I didn’t have my SHBG tested.

Your test levels won’t be accurate that soon. Just an example , I had labs done several weeks after coming off Nolvadex, my TT was 794 (250 higher than my pre cycle labs). But after a couple of months I retested and they bounced back to pre lab numbers of 550.

I wouldn’t put too much weight or thought into the current numbers, personally.

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