Quest Diagnostics different ranges for Free T based on methodology?

[nicknot]

I'm having some trouble understanding how different ranges relate to each other.

For example, the non-Dialysis Free T mehod at Quest has a range of 46-224pg/mL for 18-69yo males (Quest Diagnostics: Test Directory).

However the Dialysis Free T range shows 35-155pg/mL on my lab report.

My results came back at 240pg/mL on the 35-155 range. Does that mean they would've come back at around 350pg/mL on the 46-224 range?

If my results would've come back the same (240pg/mL) on the 46-224 range, it would mean that one of their Free T tests says I'm at the top of the normal range, and their other test says I'm completely superhuman.

In other words, both tests for the same marker would place me at completely different percentiles relative to the population, which makes no sense.

EDIT: Same thing with Labcorp for ex. Their range is 9-26ng/dL. Would I test also at 24ng/dL (equivalent to my 240pg/mL with Quest)? Or a (proportional to my Quest result) ~35ng/dL? If it's the former, again it would mean both labs place me at completely different percentiles.

How does this make any sense?

 

[madman]

I'm having some trouble understanding how different ranges relate to each other.

For example, the non-Dialysis Free T mehod at Quest has a range of 46-224pg/mL for 18-69yo males (Quest Diagnostics: Test Directory).

However the Dialysis Free T range shows 35-155pg/mL on my lab report.

My results came back at 240pg/mL on the 35-155 range. Does that mean they would've come back at around 350pg/mL on the 46-224 range?

If my results would've come back the same (240pg/mL) on the 46-224 range, it would mean that one of their Free T tests says I'm at the top of the normal range, and their other test says I'm completely superhuman.

In other words, both tests for the same marker would place me at completely different percentiles relative to the population, which makes no sense.

EDIT: Same thing with Labcorp for ex. Their range is 9-26ng/dL. Would I test also at 24ng/dL (equivalent to my 240pg/mL with Quest)? Or a (proportional to my Quest result) ~35ng/dL? If it's the former, again it would mean both labs place me at completely different percentiles.

How does this make any sense?

Forget comparing different assays let alone reference ranges!

Use the same lab, same assays (most accurate).

You should be testing FT using Equilibrium Dialysis or Ultrafiltration using the same lab/assay when comparing results.


However the Dialysis Free T range shows 35-155pg/mL on my lab report.

My results came back at 240pg/mL on the 35-155 range.


Luckily you had your FT tested using one of the most accurate assays Equilibrium Dialysis (Quest) and your levels are over the top-end.

If these are trough then peak will be higher.


post #15/16/17/18

Help with protocol

I’m on 10 weeks of trt with 60mg”s twice a week IM. Levels came back around 550 at trough and free t at 18, E2 at 56 (using hcg 400ius 2x a week). I feel okay but I know those aren’t in the optimal range. My main reasoning is I have lower shbg around 16.5 pre treatment it is now at 11.8 on trt...

www.excelmale.com

 

[madman]

What is your protocol (dose T/injection frequency) and where does your SHBG sit?

Post full set labs showing your TT, SHBG, estradiol, and RBCs/hemoglobin/hematocrit

 

[madman]

When it comes to testing FT you should be using one of these assays as it is critical when on trt to know where your FT level truly sits on such protocol.

Use Nelsons discounted labs.

1 Testosterone, Total and Free (NO Upper Limit) plus Hematocrit

2 Testosterone, Total, LC/MS, and Free (Equilibrium Ultrafiltration)

 

[nicknot]

What is your protocol (dose T/injection frequency) and where does your SHBG sit?

Post full set labs showing your TT, SHBG, estradiol, and RBCs/hemoglobin/hematocrit

I'm on 18mg/day Test C shallow IM in delts. TT was 1500ng/dL, I haven't tested SHBG this time but before TRT it was very high (80) and last time around 45 (finally within range).

E2 (ultra-sensitive) I'm still waiting for (only got partial results right now).

Everything else is good. Lipids, CBC, CMP. Hematocrit is 45%, HDL very high, LDL pretty low, etc...and I did use discountedlabs.

I understand it's important to look at the range, but I'm trying to figure out the implications of those results.

Looking at the range they gave me and my results, it looks like I'm way above range, something that's not sustainable healthily. However, maybe if I took the Labcorp FT test I'd test around 24ng/dL also and that would be withing range.

 

[madman]

I'm on 18mg/day Test C shallow IM in delts. TT was 1500ng/dL, I haven't tested SHBG this time but before TRT it was very high (80) and last time around 45 (finally within range).

E2 (ultra-sensitive) I'm still waiting for (only got partial results right now).

Everything else is good. Lipids, CBC, CMP. Hematocrit is 45%, HDL very high, LDL pretty low, etc...and I did use discountedlabs.

I understand it's important to look at the range, but I'm trying to figure out the implications of those results.

Looking at the range they gave me and my results, it looks like I'm way above range, something that's not sustainable healthily. However, maybe if I took the Labcorp FT test I'd test around 24ng/dL also and that would be withing range.

With a TT 1500 ng/dL even with highish SHBG 45 nmol/L your FT would be very high.

Although injecting daily will result in minimal peak--->trough and stable blood levels throughout the week hitting an extremely high TT 1500s with SHBG 45 nmol/L would still have your FT levels very high.

If you feel well overall, your blood markers are healthy and you are not battling any sides then leave it be.

If you were struggling on such protocol then you would easily have room to lower your dose and bring down your FT level.

Keep in mind that you need to give the protocol at least 12-16 weeks (including 4-6 weeks) for blood levels to stabilize in order to truly gauge how you feel overall regarding relief/improvement of low-t symptoms.

When first starting trt or tweaking a protocol (dose T/injection frequency) the first 6 weeks can be very misleading when looking at the bigger picture.

 

[madman]

Many men on trt overlook what is stated in post #7

My Most Recent Labs.

My protocol, 16 mg of testosterone cypionate daily, 500 iu of hcg twice weekly and no AI. Pregnenolone 10 mg and 25 mg of DHEA. My last injection before labs, about 28 hr.s. Labs are from LabCorp. Testosterone, Serum 1319 ng/dL range 264-916 Free Testosterone 47.9 ng/dL range...

www.excelmale.com

 

[nicknot]

With a TT 1500 ng/dL even with highish SHBG 45 nmol/L your FT would be very high.

Although injecting daily will result in minimal peak--->trough and stable blood levels throughout the week hitting an extremely high TT 1500s with SHBG 45 nmol/L would still have your FT levels very high.

If you feel well overall, your blood markers are healthy and you are not battling any sides then leave it be.

If you were struggling on such protocol then you would easily have room to lower your dose and bring down your FT level.

Keep in mind that you need to give the protocol at least 12-16 weeks (including 4-6 weeks) for blood levels to stabilize in order to truly gauge how you feel overall regarding relief/improvement of low-t symptoms.

When first starting trt or tweaking a protocol (dose T/injection frequency) the first 6 weeks can be very misleading when looking at the bigger picture.

I agree, I actually came down from 22mg/day where my TT was 1700ng/dL, FT 370pg/mL and E2 (ultra-sensitive) 70pg/mL (range < 29).

The super high E2 gave me nasty sides; hypertension (serious), bloating, depression, back acne, etc...

I feel much better since dropping to 18mg/day. The weird thing is that my TT dropped by only ~10% while my FT dropped by ~50%, which leads me to believe that the smaller dose made my SHBG rise again (didn't test it this time unfortunately).

I wish I could've just lowered the E2 without losing so much Free T.

 

[madman]

I agree, I actually came down from 22mg/day where my TT was 1700ng/dL, FT 370pg/mL and E2 (ultra-sensitive) 70pg/mL (range < 29).

The super high E2 gave me nasty sides; hypertension (serious), bloating, depression, back acne, etc...

I feel much better since dropping to 18mg/day. The weird thing is that my TT dropped by only ~10% while my FT dropped by ~50%, which leads me to believe that the smaller dose made my SHBG rise again (didn't test it this time unfortunately).

I wish I could've just lowered the E2 without losing so much Free T.

FT would have been ridiculously high running an absurd TT 1700 ng/dL.

You need to know where your SHBG sits on the most recent protocol.

Acne has more to do with the sensitivity of the AR (skin/scalp) and too high FT can easily cause acne/accelerated balding in the genetically prone.

No one on trt would need to be running a ridiculous TT 1600-2000 ng/dL.

Most men can easily achieve a healthy let alone high and in many cases absurdly high FT level hitting a TT 1000-1200 ng/dL range even with high SHBG.

 

[nicknot]

Most men can easily achieve a healthy let alone high and in many cases absurdly high FT level hitting a TT 1000-1200 ng/dL range even with high SHBG.

How do you explain my case then? TT at 1500ng/dL and FT only at 24ng/dL (equivalent to 240pg/mL)?

Again my TT dropped ~10% and my FT ~50%, how does that make sense?

 

[madman]

How do you explain my case then? TT at 1500ng/dL and FT only at 24ng/dL (equivalent to 240pg/mL)?

Again my TT dropped ~10% and my FT ~50%, how does that make sense?

Look at where your FT level would sit using the cFTV/cFTZ.

TT 1500 ng/dL, Albumin __, SHBG__ (use 45 nmol/L for now).

post #8/9

Thoughts on my most recent bloodwork? IS my E2 too high?

Just got my bloodwork back for 30 mg eod been on this protocol for about 3 months TESTOSTERONE, TOTAL: 1257 ng/DL (250-827) TESTOSTERONE, FREE: 226.6 pg/mL (46-224) ESTRADIOL,ULTRASENSITIVE: 61 pg.mL (< or = 29) SHBG: 30 n/Mol (10-50) I feel pretty good, but Ive been breaking out like crazy...

www.excelmale.com

 

[nicknot]

Look at where your FT level would sit using the cFTV/cFTZ.

TT 1500 ng/dL, Albumin __, SHBG__ (use 45 nmol/L for now).

post #8/9

Thoughts on my most recent bloodwork? IS my E2 too high?

Just got my bloodwork back for 30 mg eod been on this protocol for about 3 months TESTOSTERONE, TOTAL: 1257 ng/DL (250-827) TESTOSTERONE, FREE: 226.6 pg/mL (46-224) ESTRADIOL,ULTRASENSITIVE: 61 pg.mL (< or = 29) SHBG: 30 n/Mol (10-50) I feel pretty good, but Ive been breaking out like crazy...

www.excelmale.com

I just did, and for my FT to come back at 240pg/mL (24ng/dL), my SHBG would have to be at 70nmol/L, which is not impossible at all since pre-TRT I was at 80nmol/L.

And it's definitely possible my SHBG has rebounded from the low of 45nmol/L after I lowered my dose (higher doses lower SHBG more).

 

[madman]

I just did, and for my FT to come back at 240pg/mL (24ng/dL), my SHBG would have to be at 70nmol/L, which is not impossible at all since pre-TRT I was at 80nmol/L.

And it's definitely possible my SHBG has rebounded from the low of 45nmol/L after I lowered my dose (higher doses lower SHBG more).

Have no idea where your SHBG sits of now and as you can see in higher cases of SHBG there is a big difference in FT levels between cFTV vs cFTZ.

 

[madman]

I just did, and for my FT to come back at 240pg/mL (24ng/dL), my SHBG would have to be at 70nmol/L, which is not impossible at all since pre-TRT I was at 80nmol/L.

And it's definitely possible my SHBG has rebounded from the low of 45nmol/L after I lowered my dose (higher doses lower SHBG more).

T dose was only dropped from 22 mg/day (154 mg/week)--->18 mg/day (126mg/week).

Even though T-dose was lowered by 28mg/week your TT went from 1700 ng/dL--->1500 ng/dL which is still very high.

Have no clue where your SHBG sat when TT was 1700 ng/dL let alone now 1500 ng/dL as it was not tested.

 

[xqfq]

I've performed the Quest lab on the same day as Labcorp (about 20 minutes apart). Here is an example result:

Quest:
Testosterone: 1010 ng/dL
Free T: 189.2 pg/mL (Range: 35.0-155.0 pg/mL) ("Dialysis")

Labcorp:
Testosterone: 912 ng/dL
Free T: 21.7 pg/mL (Range: 8.7-25.1)

Based on this result as well as my subjective experience, I believe the Labcorp results are ~ 10x the quest results. But I am not sure.

I dislike the Quest test - I don't understand how it is so inexpensive if it's truly LC/MS/MS and equilibrium dialysis.

I performed a labcorp LC/MS/MS and free T by ultrafiltration and the results were wildly different (relative to the range upper limit) from the Quest "dialysis" results, when on the same protocol.