Different Lab Ranges. Libido. Confused with Bloodwork Results

Pharma TRT
1

Several years ago I had multiple total testosterone tests in the 200-300 range after a vasectomy, and was very close to starting TRT. I started tracking my labs roughly every 6 months. Posted here and got some great feedback, and I yet again find myself a bit confused.

I’ve spent years optimizing diet and exercise, and testing just about everything I can. Sleep apnea tested, vitamin D, sleep tracking, etc. Fixed a few things along the way, but I can genuinely say this is near “peak me” now if you will and I’m back to my college physique. Muscular, ~15% BF, 7-8 hours sleep, great diet, no drinking/smoking/etc…

I consistently now get TT results in the ~330 range at my doctors (a major health corporation). Haven’t had anything in the 200’s for a long time.

Felt like death in the 200’s. Now I feel noticeably better, less brain fog, I can recover better from workouts now… but literally zero libido. Zero. No porn, no masturbation (haven’t had the desire to in years), very attracted to my wife and we have sex roughly once a week… but there is zero physical “need/urge/desire”. I could go weeks without sex/release and physically I wouldn’t care. I really, really miss that physical desire and I know my wife has noticed that missing.

With TT tests in the low 300’s, my thinking was perhaps that’s still the issue now that I can confidently say everything else is optimized.

But this is where I get confused… if I go to LabCorp, I get noticeably different results. And LabCorp appears to be what most people are referencing when looking at bloodwork. I’m consistently in the 420-430 range with LabCorp. And that makes me start to think it’s not testosterone related and re-question if I want to try/take on everything involved with TRT.

Latest labs from LabCorp (I’m early 40’s)

TT: 435 ng/dL (264-916)
Free T: 10 pg/mL (6.8-21.5)
LH: 7.1 (1.7-8.6)
SHGB: 31.6 (16.5-55.9)
Estradiol: 17.4 (8.0-35.0)
PSA: 0.9
IGF-1: 216 ng/mL (84-270)
Hemoglobin: 16.5 (13.0-17.7)
Hematocrit: 48.6 (37.5-51.0)
All the Thyroid/Prolactin/cholesterol/etc in range.

Has anyone else found themselves with consistently different results from different labs like this / am I missing something? I feel better, but still have zero libido, and these consistent 400+ results from LabCorp have me questioning TRT.

Appreciate any insight!

2

The labs can use different methods to get you a total testosterone result. LC/MS-MS is usually what you want for accuracy.

Also your testosterone varies throughout the day. Assuming same diet and good sleep, it will be highest in the morning and taper down through the day. So timing of the labs matters also.

I was in a similar situation as you. Had labs at 320 TT, fixed my sleep and diet for months. was able to get up to 450ng/dl on my own. Started TRT at that point and my libido went from good to almost annoyingly too high.

3

This is pretty mediocre results for such a high normal LH, even the estrogen is low. A bit more about the ranges, those ranges include children who haven’t hit puberty.

My LabCorp ranges for the sensitive E2 test is 20-35 pg/mL.

We recommend 12.1 nmol/L as a lower limit of normal for TT level. However, due to individual differences in testosterone sensitivity some men may exhibit symptoms of hypogonadism with TT concentrations above this threshold, and may benefit from TRT. TRT may be reasonably offered to symptomatic men with testosterone concentrations higher than 12 nmol/L based on clinical judgment, and certainly if free T concentrations are reduced.

The prevalence of hypogonadal symptoms increases with TT levels below 12.1 nmol/L (350 ng/dL). However, Zitzmann et al. have shown that testosterone deficiency symptoms may also be seen with TT levels as high as 15 nmol/L. This study showed that the prevalence of loss of libido or vigor increased at testosterone concentrations below 15 nmol/L (433 ng/dL) ( p < 0.001),

Unfortunately, no consensus has been reached regarding the lower TT threshold defining TD, and there are no generally accepted lower limits of normal TT. This lack of consensus follows from the fact that no studies have shown a clear threshold for TT or free T that distinguishes men who will respond to treatment from those who will not.

Meanwhile the number of CAG (cytosine–adenine–guanine triplet) repeats in androgen receptor differs in men and influences the androgen receptor activity. Hence testosterone sensitivity may vary in different individuals.

The same applies to androgen receptor gene CAG repeat lengths >24 in the presence of symptoms and normal testosterone levels may be considered as a state of preclinical hypogonadism.

1 Like