Target T levels & Defy

[slicktop]

The healthy normal range is considered to be 16-31 ng/dL.

See, that's what drives me crazy is all the GD conversions. So I was at 32.97 ng/dl, which translates to 329.7 pg/mL. The LabCorp test is in pg/mL not ng/DL, the Tru-T calculator gives results in nMol/L and ng/dL. BAAAAGH. So again, unless I'm doing this wrong, Tru-T suggests that I should have 10x more free-t in my system than LabCorp does?

 

[Jason Sypolt]

The difference between direct free testosterone and Tru-T is staggering. Plugging in my own values, at one point my direct free testosterone was 19.5 pg/mL(6.8-21.5) but Tru-T was at 329.7 pg/mL. WTF??

I can't answer the question about switching testing methodologies, that would be up to Dr. Saya as Medical Director. Patients are also certainly welcome to have a say in their labs and help select one over the other. This happens for example between selecting the LCMS testosterone test or not.

Free T used to be extremely important to me when I (over)analyzed every result, but not really anymore. I just used it as an example. Part of the reason is that I just don't have time for that now, but I'm looking at overall balance, not counting every grain of sand.

This is really off topic but relates to the Free T test being discussed:
I would be cautious in some cases in reading results like that if they came from LabCorp because myself, Nelson, and several others have reported to LabCorp what appears to be a random error in what they report back in units for Free T tests such as direct. They ask for examples which are sent and then they don't respond. What happens is that sometimes they will show Free T results saying they are measured in pg/mL, but that looks to be incorrect and the unit of measure should be ng/dL instead. Here are some examples:

Example 1:
Total T: 734 ng/dL
Free T: 206 pg/mL

You can divide pg/mL by 10 to convert to ng/dL. That's 20.6 ng/dL or 2.8% Free to Total and perfectly reasonable.

Example 2 (same person, after a small increase in dosage):
Total T: 929.2 ng/dL
Free T: 29.6 pg/mL

So in example 2, LabCorp is saying that this person had 2.96 ng/dL (if you convert to the same units) Free T, or 0.319% of 929.2 which is pretty much stating that they now have no Free T at all. Free T in Example 2 should have either been reported in ng/dL or the result should have been multiplied by 10. I have gone back to look at my own results and have seen the same random occurrence.

 

[slicktop]

I have a lot of data. The correlation is not great:
View attachment 8979
The clincher is when I compare free testosterone to dose. Here's Tru-T:
View attachment 8980
Here's the direct test:
View attachment 8981

That's the most convincing argument for Tru-T that I've ever seen. Thank you for sharing.

 

[Cataceous]

...
I would be cautious in some cases in reading results like that if they came from LabCorp because myself, Nelson, and several others have reported to LabCorp what appears to be a random error in what they report back in units for Free T tests such as direct. They ask for examples which are sent and then they don't respond. What happens is that sometimes they will show Free T results saying they are measured in pg/mL, but that looks to be incorrect and the unit of measure should be ng/dL instead. Here are some examples:
...

This is why the exact test must be specified, along with the normal range. LabCorp is offering at least four different types of free T tests, every single one with a different range. The direct test is the one whose range has nothing to do with actual free T concentrations, topping out in the 20s pg/mL. The other ones are at least going to be in the tens of ng/dL. These include calculated, equilibrium ultrafiltration, and equilibrium dialysis.

 

[Cataceous]

That's the most convincing argument for Tru-T that I've ever seen. Thank you for sharing.

I was surprised myself at the really good linearity of the Tru-T response to dose. The data support a couple ideas: first, that the underlying metabolic clearance of testosterone can be pretty static, at least in some—the measurements were taken over four years; and second, that the testosterone dose proportionally drives free testosterone, not total.

 

[xqfq]

For me, direct T and Trut T are somewhat linear.

In Sept, my direct T was 24.7 9 (6.6-18.1), truT (48.6 16-31). (That was 20 days after Nebido, my total T was 1492, I was curious what levels were at a peak.)

We know for E2, c-reactive protein can raise your standard E2 test level Vs the sensitive E2 test.

I wonder what makes direct T measurements not accurate for some people and more accurate for others?

Tru-t problem for me, I don't often check shbg and it does change, so I can't really tell what my trut result would be in more than half my test results.

But for me, I don't try and micromanage levels, so total T from 600-1500 is OK by me, and that directly changes everything else.

And I am getting to the point where I am tending towards only checking at most once a year.

I’m a little on the fence about the accuracy or value of the TruT calculator in the absence of mysterious side effects. For my own labs and symptoms (tracked using Nelson’s TRT Analyzer), the older free T calculated method and the direct free T more closely match my symptoms (numbers relative to the provided ranges) than the TruT calculator.

I’ve also started using the TruT calculator on bodybuilders’ lab work and it seems to be even more subjectively wrong there, too. For instance, if you use this IFBB pro’s HRT numbers (https://www.youtube.com/watch?v=J4t4BeQaL8g), you’ll get a physiologic TruT free T. But I think he’s likely to be 2-2.5x the upper end of free T range given that he maintains his LBM on his HRT dose. His direct free T labs show numbers in accordance with what I’d expect.

I’ve done this same thing with other bodybuilders and I find similar, making me think the TruT calculator is missing something, or is predictive only for the majority of people but for a given individual may not be accurate. Their data shows this, if I recall correctly - there are consistently outliers in their model, as it’s predictive but not exact. I’ve contacted the authors with my own concern that the calculator doesn’t take into account magnesium status (a known modulator of free T), but haven’t heard back.

 

[Cataceous]

I’m a little on the fence about the accuracy or value of the TruT calculator in the absence of mysterious side effects. ...

When in doubt use equilibrium dialysis measurements. We did find contradictions with Tru-T in this guy's measurements that we can't explain, unless the SARM was doing something weird.

Nonetheless, direct RIA is likely the least accurate of the commonly used methods for determining free T. Per the Endocrine Society, it suffers from "Poor accuracy, sensitivity, and between-laboratory comparability: Major biasing effects due to dilution of serum samples; Significant binding of the analog to serum proteins; Lack of parallelisms between measurements of serially diluted serum samples and FT."[1]

 

[xqfq]

When in doubt use equilibrium dialysis measurements. We did find contradictions with Tru-T in this guy's measurements that we can't explain, unless the SARM was doing something weird.

Nonetheless, direct RIA is likely the least accurate of the commonly used methods for determining free T. Per the Endocrine Society, it suffers from "Poor accuracy, sensitivity, and between-laboratory comparability: Major biasing effects due to dilution of serum samples; Significant binding of the analog to serum proteins; Lack of parallelisms between measurements of serially diluted serum samples and FT."[1]

Maybe I will get the equilibrium dialysis soon. It would be interesting to see. One thing I cannot explain is that my RIA "direct free testosterone" numbers almost always line up with the Vermeulen calculated free T. This, along with my subjective experience, makes me lean toward trusting them more than the TruT numbers, at least for now:

Free T ('direct'): 30.0 pg/mL
Vermeulen Free T: 30.3 ng/dL
TruT: 48.53 ng/dL

Free T ('direct'): 10.3 pg/mL
Vermeulen Free T: 14.6 ng/dL
TruT: 25.66 ng/dL

Free T ('direct'): 12.6 pg/mL
Vermeulen Free T: 12 ng/dL
Tru: 21.39 ng/dL

Free T ('direct'): 24.4 pg/mL
Vermeulen Free T: 27.3 ng/dL
TruT: 40.59 ng/dL

Free T ('direct'): 29.6 pg/mL
Vermeulen Free T: 28.1 ng/dL
TruT: 38.20 ng/dL

As a note, my hs-CRP is undetectably low, so perhaps I have less cross-reactivity (if that's a possibility with this assay)

 

[Cataceous]

Maybe I will get the equilibrium dialysis soon. It would be interesting to see. One thing I cannot explain is that my RIA "direct free testosterone" numbers almost always line up with the Vermeulen calculated free T. This, along with my subjective experience, makes me lean toward trusting them more than the TruT numbers, at least for now:
...

I'm not sure if it's important, but with these numbers the best correlation is between Vermeulen and Tru-T (R^2 = 0.941). The next best is between direct and Vermeulen (R^2 = 0.936). The worst is between direct and Tru-T (R^2 = 0.840).

 

[xqfq]

Maybe I will get the equilibrium dialysis soon. It would be interesting to see. One thing I cannot explain is that my RIA "direct free testosterone" numbers almost always line up with the Vermeulen calculated free T. This, along with my subjective experience, makes me lean toward trusting them more than the TruT numbers, at least for now:

Free T ('direct'): 30.0 pg/mL
Vermeulen Free T: 30.3 ng/dL
TruT: 48.53 ng/dL

Free T ('direct'): 10.3 pg/mL
Vermeulen Free T: 14.6 ng/dL
TruT: 25.66 ng/dL

Free T ('direct'): 12.6 pg/mL
Vermeulen Free T: 12 ng/dL
Tru: 21.39 ng/dL

Free T ('direct'): 24.4 pg/mL
Vermeulen Free T: 27.3 ng/dL
TruT: 40.59 ng/dL

Free T ('direct'): 29.6 pg/mL
Vermeulen Free T: 28.1 ng/dL
TruT: 38.20 ng/dL

As a note, my hs-CRP is undetectably low, so perhaps I have less cross-reactivity (if that's a possibility with this assay)

It turns out I have had equilibrium dialysis performed. These are results from Quest’s lab order code 36170, which is stated to be MS for total testosterone and equilibrium dialysis for free testosterone, as per https://testdirectory.questdiagnostics.com/test/test-detail/36170/testosterone-free-dialysis-and-total-ms?p=r&cc=MASTER

Testosterone 1074
Free testosterone 155.5 pg/mL = 15.55 ng/dL.
(Range: 35.0-155.0 pg/mL)

My SHBG, as measured a few days prior in a separate lab, was 48. Using the TruT calculator, my free T is expected to be 34.59 ng/dL, which is over twice as much as dialysis states. To have the calculator be accurate, my SHBG would have to have been 200+, which I consider nearly impossible.

Another of the same lab during another checkup:

T 902
Free T 144.3 pg/mL (Range: 35.0-155.0 pg/mL)
= 14.4 ng/dL

TruT puts me at 30.83 ng/dL according to an SHBG of ~36 drawn a few days later. Again TruT is off by over 2x.

In my case, TruT is not remotely accurate. Perhaps I’m missing something and the Quest lab test is reporting figures in some kind of units that only apply to their test and can’t be generalized to the same values as TruT. E.g. these reference ranges and units aren’t aligned somehow?

According to this source (https://www.researchgate.net/publication/257347511_Free_testosterone_by_direct_and_calculated_measurement_versus_equilibrium_dialysis_in_a_clinical_population), “ These results support the clinical use of both RIA and cFT as measures of FT. Due to numerical differences, each test requires its own set of reference values.“

If anyone has an idea, please chime in!

 

[Cataceous]

...
If anyone has an idea, please chime in!

Taking a look at the graphs puts things in a better perspective and makes the differences seem less dramatic. Perfect correlation is when all points fall on a straight line. The lack of SHBG readings at exactly the times of the T readings could be somewhat problematic for the calculated methods. @madman: This seems to be a case where Vermeulen marginally outperforms Tru-T.

 

[fifty]

Given the low price if that quest test, I question if it truly is equilibrium dialysis on free test. We talked about this in the past on here.

 

[Cataceous]

Given the low price if that quest test, I question if it truly is equilibrium dialysis on free test. We talked about this in the past on here.

What is the price? Either it's equilibrium dialysis or they're brazenly lying about it. Or is there such a thing as a half-baked, cheapo ED test?

 

[xqfq]

What is the price? Either it's equilibrium dialysis or they're brazenly lying about it. Or is there such a thing as a half-baked, cheapo ED test?

I wondered this too. It’s like $40 for total and dialysis free. But all of the other dialysis tests are $400+.

I think this is the same Quest test that Dr Thomas O’Connor orders as part of his standard panel and there might have been cross reactivity with nandrolone in at least this case:

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Which makes me think there’s something off with this Quest lab. I’d be inclined to run it and a labcorp dialysis lab at the same time but all the other labs charge 400+ for this.

If someone could link me a previous discussion of this I’d love it.

 

[fifty]

Previous discussion was nothing amazing. We were trying to price out a good free T test. We concluded that discount labs ultrafiltration was the best value for an accurate test at ~$90.

Testosterone, Free, Equilibrium Ultrafiltration With Total Testosterone, LC/MS- No Upper Limit

 

[tareload]

Response from LabCorp About Their Incorrect Unit Usages For Their Free Testosterone - Direct - Test

I've been irked for a year by the apparent incorrect unit usage for the particular Free Testosterone test mentioned above. I periodically reach out to whatever relevant executive I can find. No luck for months until the below correspondence. In brief his explanation doesn't hold up in my view...

www.excelmale.com

Regarding units of labcorp direct free T test and comparison of free T methods.

 

[bixt]

I have a lot of data. The correlation is not great:
View attachment 8979
The clincher is when I compare free testosterone to dose. Here's Tru-T:
View attachment 8980
Here's the direct test:
View attachment 8981

For me, the sum and substance of this post is that 70mg/week is the ideal dose for anyone.

This lines up perfectly with that massive thread of posted results over at professional muscle, where tons of guys are using 10mg daily (70mg / week) and like all of them have free T in the mid to late 20s. Probably direct measurments, they arnt clued up like us in that respect.

 

[tareload]

that 70mg/week is the ideal dose for anyone.

I'd rephrase that 70 mg/week equivalent of test ester is a reasonable starting regimen given MED philosophy. Based on an individual's rate of fT elimination, they may need more or less to reach proper eugodal TT/fT levels and symptom resolution.

This is a considerably smaller starting dose regimen than you'd be led to believe by watching Youtube TOT channels and or listening to anti-aging clinics (many that start ignorant patients at 200 mg/week of test ester).

What is TRT and What is NOT TRT

What is TRT For the curious minds or folks seeking a better understanding, TRT stands for Testosterone Replacement Therapy. The R stands for replacement, not enhancement, or elevation. Sometimes there seems to be some confusion between the TRT and pharma section. Note, after discussion with...

forums.t-nation.com

What is TRT and What is NOT TRT

Note: I originally posted this over at T-Nation so hope it's ok if I share it here @Nelson Vergel. Had an interesting and lively exchange over there with one of the proponents of the "TOT" protocol (Testosterone Optimization Therapy as it is called). This short summary gives guys a look of...

www.excelmale.com

 

[bixt]

Fantastic charts! It seems to appear to my eye that the dose response is logarithmic right?

The small dose of 70mg / week yields 800nd/dl, large dose of 200mg/week seems to yield 1200ng/dl.

So the large dose is almost 2.9x the small dose and yet yields only 1.5x the increase in TT?

p.s. For those wondering what "highpull data" is, its data from a physician who goes by that name over at T Nation. His data does not conform to the other regressions though.

 

[bixt]

His data does not conform to the other regressions though.

Or does it? With performing an actual regression with 60+samples on his data, its hard to say