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Got Lab Bloodwork. Confused About Free T

I’ve been suspecting that low T might be to blame for my issues (very hard time gaining mass / muscle / strength, aswell as some mild depression-like symptoms that come and go)

Got bloodwork done last week, with the following results:

Free testosterone: 17.4 pg/ml (range: 7 - 22.7)
Total Testosterone: 601 ng/dl
SHGB: 36 nmol/l (range: 11.6 - 86.9 nmol/l)

DHEA-S: 584 µg/dl (range: 211 - 492, average being 353) - my doctor told me that this high level is ‘probably fine’, while googling it before my very eyes…

Estradiol: 31 pg/ml (range: 7.63 - 42.6)
Progesterone: 0.3 ng/ml (range: 0.2 - 1.4)
Cortisol: 160 ng/ml (range: 31 - 194)

Total T seems alright, not perfect but not ‘I need TRT right now’ territory. However, free T has me confused. I’ve read multiple resources stating that the range for free T is somewhere around 50-180 pg/ml for my age (22), which would mean that 17.4 is extremely low. But the lab doesn’t use that range, instead they use a range in which my result seems ok. Do they use a different method of measuring free t than others, thus the different range?

Would greatly appreciate if someone was knowledgeable enough to tell me if this bloodwork is indicative of being a TRT candidate (wich is something I’d not pursue unless absolutely needed, seeing as my country isn’t very… cooperative regarding TRT), or why there’s so many different ranges for free T online.

As far as you having difficulty gaining mass/muscle strength there are genetic factors as well. The mild depression that comes and goes is normal part of life, we have our ups and downs through life. Free T measurements are problematic and almost useless which is why doctors almost exclusively fixate on the Total T.

The Total T and SHBG measurements are more accurate, but even the Total T isn’t perfect because if you were to split up the sample into two or three, you would get a different result each time. You don’t have low-T, you are not encountering any of the classic symptoms, fatigue, low libido and problems with erections are the common ones.

The only thing I see is slightly overactive adrenals. By the way 501 ng/dL is NOT “extremely low”. The Free T calculator has your Free T at the bottom of the 2% 2-3% which is normal.

Are you certain the pressure you’re putting on yourself into gaining muscle and failing to do so could be the reason for the mild depression?

There are no standards, up until now hormones as a whole have been ignored in western medicine and the average doc is out in left field as far as hormone knowledge is concerned.

When a laboratory is attempting to open its doors they run standardized samples against their equipment and processes to determine the ranges that they will be reporting. If you’re in the range at one, you’d be in the range at another lab.

There is some problem with units reported by Labcorp that I think is causing this confusion. Total T is usually given in ng/dL in the US. Free T is either given in ng/dL or pg/mL. Free T is typically 2-3% of total T so if your total T is 600 ng/dL then in the same ng/dL free T should fall in the range of 12-18 ng/dL. Quest Diagnostics gives their free T values in pg/dL and the range is 35.0 - 155.0 pg/mL or I think something like 50.0 - 210 ng/dL depending on which test you take with them. Lab Corp says that their values are in pg/mL but they actually appear to be in ng/dL with a range like 7 - 22.7.

I just got my labs back from Quest Diagnostics and my total T is 818 ng/dL. My free T is 184.7 pg/mL which would equal 18.47 ng/dL. That makes a hell of a lot more sense to me. The tests used by Labcorp and Quest can’t be that different. So that “50-180 pg/mL” range would be equal to 5-18 in ng/dL.

Now everyone on this forum has their own idea of what constitutes optimal total and free T with something in the 20-24 ng/dL range for free T being quite popular. Obviously yours and mine are slightly below that but by no means are they low. Before starting TRT my free T was 38 pg/mL and I had all the symptoms. At that point I was at the bottom of the range but still technically in range. After starting I was initially at 79 pg/mL and most but not all of my symptoms were resolved. I had the doc increase my dose and now I’m at 184.7 pg/mL and everything is great. Now could things be even better if my free T were above 20? I don’t know. Maybe so, maybe not. And there are other factors to consider - impact on HDL and LDL cholesterol, increases in hemoglobin and hematocrit, acne (I’ve gotten a few pimples even at my current level which I haven’t experienced since I was a teenager), etc. I’m inclined to leave well enough alone at this point.

That makes sense

Should’ve mentioned, I live in Germany and the test was done by some local lab in my city. I’ve had the same train of thought though.

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Labcorp is global so they could still be the company doing the work behind the scenes even in Germany I bet. Or the local lab is using the same protocols. At any rate, it doesn’t make sense that a range like 7-22.7 could be in pg/dL as it should be 2-3% of total T.

Correction, it wasn’t a local lab, a quick google search reveals they’re all over the EU apparently, they’re called Synlab. But their range of reference is very similar to Labcorp’s, from what I read