Fast Metabolizers?

[Gianluca]

No denying there are a few people reporting response-to-dose much lower than normal. Even in the past day:

High dose low total

Hey guys I had a few questions. My drs. Have been useless!!!! original total t- 159 and 213 He started me on 100mg a week total t came back after being on 100mg at 133 so it dropped since November I have been on 200mg a week... total t always comes back at 430-480 injecting at home doing .33...

www.excelmale.com

switched to ED protocol with same dose and FT dropped??

Current protocol is 26mg daily, .13ml T-CYP. Free Test come back at 50 ng/dl Labcorp, but my doc explained the assay they used is incorrect, and since my SHBG at 11, albumin at 5, he calculated a true FT of about 22, TT came back at 615. I wanted to run the test again, this time with Quest Lab...

www.excelmale.com

Contributing factors may sometimes include low SHBG and high body weight. Presumably they also have high-end metabolic clearance rates for testosterone. Only detailed measurements under controlled conditions would adequately explain the reported observations.

The bottom line though is that 3-9 mg is the reported range for daily testosterone production in men, and this probably represents at least two standard deviations about the mean. In other words, exogenous testosterone dosed in this range will produce normal serum levels in the vast majority of healthy men. Translated to TRT, those who need more than about 120 mg T cypionate per week to reach at least low-normal average serum T are uncommon in the population at large.

This is similar to my own response and is not particularly extreme. Basically, 4 mg of testosterone daily is sufficient to maintain normal serum levels. It presumably does reflect a below-average MCR(T).

I heard first dr Mark Gordon mentioning the body producing an amount of Testosterone similar to the 3-9mg you noted here, my question is, what type of men are producing 3-9mg per day? the modern men with no sex drive, average unhealthy with some type of insulin resistance, metabolic syndrome, or the men who feel the best in regards to, insulin resistance, body mass, sex drive, motivation/drive in life, sleep and overall wellbeing? because I don't understand then, why most men need at least double the 3-9mg daily on TRT to achieve "normal" levels and symptoms resolution. Perhaps but most likely, nothing work the best as our own natural hormone production, and when exogenous Testosterone is used, more is needed?. Or 3-9mg daily refers to unhealthy individuals

 

[Cataceous]

... what type of men are producing 3-9mg per day?...

The exact origin of the oft-cited 3-9 mg daily T production rate isn't clear to me. Sifting through the studies I find that most are based on healthy young men—typically in their 20s. Example. In this particular study one standard deviation is about 2 mg T/day. So the 95% range of +/- 2 SDs is about 3-11 mg T/d.

...because I don't understand then, why most men need at least double the 3-9mg daily on TRT to achieve "normal" levels and symptoms resolution. ...

The supposition is false. The large majority of men can achieve "normal" levels and symptom resolution with 3-9 mg T per day. I've pointed out that Xyosted, which is just injectable testosterone enanthate, only comes in doses of 50, 75 and 100 mg per week. This translates to 5, 8, and 10 mg T per day. Do you really think the manufacturers would exclude some large fraction of the market?

 

[Gianluca]

The exact origin of the oft-cited 3-9 mg daily T production rate isn't clear to me. Sifting through the studies I find that most are based on healthy young men—typically in their 20s. Example. In this particular study one standard deviation is about 2 mg T/day. So the 95% range of +/- 2 SDs is about 3-11 mg T/d.


The supposition is false. The large majority of men can achieve "normal" levels and symptom resolution with 3-9 mg T per day. I've pointed out that Xyosted, which is just injectable testosterone enanthate, only comes in doses of 50, 75 and 100 mg per week. This translates to 5, 8, and 10 mg T per day. Do you really think the manufacturers would exclude some large fraction of the market?

I wish I was one of these men! I don't think what I'm going to say right now could make sense in regards to Testosterone supplementation, but staying on the "fast metabolizer topic", and knowing you have been around more than me in different forums, have you ever seen in men a homeostatic effect, over a prolong time on Testosterone supplementation without accounting the lowering of SHBG? the more is supplemented the more is excreted?

 

[Cataceous]

I wish I was one of these men! I don't think what I'm going to say right now could make sense in regards to Testosterone supplementation, but staying on the "fast metabolizer topic", and knowing you have been around more than me in different forums, have you ever seen in men a homeostatic effect, over a prolong time on Testosterone supplementation without accounting the lowering of SHBG? the more is supplemented the more is excreted?

I think you're asking whether the underlying metabolic clearance rate for testosterone—that's independent of SHBG—can change significantly over time due to TRT. I haven't seen research that's explored this directly. I can say that over a period of several years on TRT my underlying clearance rate did not appear to change; I can multiply my testosterone dose rate by a fixed constant to accurately predict the resulting free testosterone at steady state. There's also a study showing that this kind of linearity applies to groups of men taking various doses of testosterone, going as high as 600 mg/week.[R] The treatment period in the study was 20 weeks, so at least in this time frame there was no obvious dose-dependent divergence in underlying testosterone clearance rates.