Which value is correct?

[drpub2112]

OK so here are my 6 week labs on TRT from Lab Corp.

TT = 1008 264 - 916
FT = 16.9 7.2 - 24.0
E(Sensitive) = 33.4 8 - 35
SHGB = 30 19.3 - 76.4
ALBUMIN = 4.9 3.8 - 4.9
TCHOL = 183 100 - 199
HDL = 38 > 39
LDL 127 0 - 99

Before starting TRT my TT was 430 and TT was 6.5.

When I plug my numbers into a free testosterone calculator, I get a FT of 23.5 ng/dL = 2.33 %. It seems that Lab Corp always gives me a value WAY below what is calculated with TT, SHGB, and albumin. I know that the direct method is considered inaccurate, but I'd like to understand why other people with 1000 TT have high FT lab results from the same lab. My SHGB is 30 so it's near the low end of the range from what I can gather.

Anyhow, if anyone can shed some light I'd appreciate it. I'm assuming that the calculated number is closer to accurate. Thanks in advance.

 

[Vince]

Have your magnesium levels check. Good magnesium levels will increase your free testosterone.

 

[tareload]

Enjoy...

Public Service Announcement: "Piss Poor" Direct RIA fT measurement (HELP is on the way)

Hey Folks, thought I would update the graph for free T reference ranges based on LC-MS/MS+ED and compare with Labcorp's direct RIA fT reference range. What the hell do you do with with your direct fT measurement if you want to compare with equibrium dialysis reference ranges? Take the Labcorp...

www.excelmale.com

Always attach units to measurements if you can. That will start you on the process outlined in the link.

In your case the heuristic doesn't work too well. Converted you get about 12 ng/dl with direct vs your calculated estimated. Truly piss poor !

 

[drpub2112]

Enjoy...

Public Service Announcement: "Piss Poor" Direct RIA fT measurement (HELP is on the way)

Hey Folks, thought I would update the graph for free T reference ranges based on LC-MS/MS+ED and compare with Labcorp's direct RIA fT reference range. What the hell do you do with with your direct fT measurement if you want to compare with equibrium dialysis reference ranges? Take the Labcorp...

www.excelmale.com

Always attach units to measurements if you can. That will start you on the process outlined in the link.

In your case the heuristic doesn't work too well. Converted you get about 12 ng/dl with direct vs your calculated estimated. Truly piss poor !

Piss poor, really? My cFT using Vermeulen method is 23.5 ng/dL. Using the TruT calculator it's like 32+ ng/dL. I was just wondering why such a discrepancy between the lab corp and the calculated values.

"In your case the heuristic doesn't work too well."

I think that's right. The info in that thread doesn't make sense at all. Thanks tho.

 

[tareload]

The info in that thread doesn't make sense at all.

Thanks for the feedback. Yeah I am probably aiming too high to expect many folks to invest any time learning and understanding this topic. Appreciate the info.

 

[Nelson Vergel]

When I plug my numbers into a free testosterone calculator, I get a FT of 23.5 ng/dL = 2.33 %. It seems that Lab Corp always gives me a value WAY below what is calculated with TT, SHGB, and albumin. I know that the direct method is considered inaccurate, but I'd like to understand why other people with 1000 TT have high FT lab results from the same lab. My SHGB is 30 so it's near the low end of the range from what I can gather.

Do you know which test your doctor (or you) ordered? LC/MS or ECLIA?

 

[drpub2112]

Hi Nelson, thanks for the reply. The FT test by Lab Corp was the Direct analog enzyme immunoassay (EIA). I know that's the one that's the most inaccurate.

Now that I've lurked around and read a bit more, I think I have the answer to my question. I'm sure my FT levels are closer to the calculated levels than the direct measurement so I'm comfortable with my numbers. It just seems weird to me that the lab would report mid-range FT with slightly above range TT. I was expecting to have a high SHGB that was suppressing the FT so I tested it, but it came back at 30nmol/l.

A cFT of 24 ng/dl using Vermeulen formula puts me at the top of his range, and 32 ng/dl is the top of the TruT range, so it seems like I'm right where I think I want to be at this point. Right now, I feel lucky that my starting dose put me right at the top of physiological normal without needing an AI.

I can accept that the LabCorp FT test is just unreliable. BTW... I've been ordering labs through LEF but I'm going to give discountedlabs.com try moving forward. I know I can get the accurate FT test there at a good price!!!

Thanks for all you do.