Target T levels & Defy

[bixt]

Or does it? With performing an actual regression with 60+samples on his data, its hard to say

* without performing the regression

I see I cant edit posts anymore

 

[Cataceous]

...It seems to appear to my eye that the dose response is logarithmic right?
...

It's a logarithmic scale.

It's interesting to reverse the Vermeulen calculation and graph total testosterone as a function of free testosterone (SHBG = 30 nMol/L, albumin = 4.3 g/dL):

Look familiar?

On a linear scale, and including data to the origin:

 

[tareload]

Fantastic charts! It seems to appear to my eye that the dose response is logarithmic right?

The small dose of 70mg / week yields 800nd/dl, large dose of 200mg/week seems to yield 1200ng/dl.

So the large dose is almost 2.9x the small dose and yet yields only 1.5x the increase in TT?

p.s. For those wondering what "highpull data" is, its data from a physician who goes by that name over at T Nation. His data does not conform to the other regressions though.

As @Cataceous mentioned I transformed the y-axis to logarithmic scale. Here's the plot generated from 2018 paper on linear ordinate scale:



Dose response is very linear and I put the linear regression equations on the graph for the reader.

Now here's the same plot with "highpull's data" on the linear y-axis:

Here it is again with the transformed log scale:


Observe "highpull"'s data set falls almost exclusively within the 2.5-97.5 percentile region as you might expect if the 2018 paper correctly sampled from a population of men with various rate of fT elimination. In fact since the sample size for each dosage was on the low side they had to estimate the confidence intervals using a bootstrap t-scoring method):

Population Pharmacokinetic/Pharmacodynamic Modeling of Depot Testosterone Cypionate in Healthy Male Subjects - PubMed

A randomized, double-blind clinical trial was conducted to investigate long-term abuse effects of testosterone cypionate (TC). Thirty-one healthy men were randomized into a dose group of 100, 250, or 500 mg/wk and received 14 weekly injections of TC. A pharmacokinetic/pharmacodynamic (PK/PD)...

pubmed.ncbi.nlm.nih.gov

Why did I use log-scale? So I could make the region from 100-1,000 ng/dl take up the same area as the region from 1000 to 10,000 ng/dl. Let's the reader get a different zoomed-in view of the physiologic region. Also shows the absurdity of the debate I stupidly get in routinely with TOT apologists where they claim 150-175 mg/week of test ester is the minimum starting dose to get the in the door at Club "Optimization".

Note: I also did the same analysis using Bhasin's seminal work which provides stratification by patient age (old vs young):

What is TRT and What is NOT TRT

Note: I originally posted this over at T-Nation so hope it's ok if I share it here @Nelson Vergel. Had an interesting and lively exchange over there with one of the proponents of the "TOT" protocol (Testosterone Optimization Therapy as it is called). This short summary gives guys a look of...

www.excelmale.com

 

[tareload]

It's a logarithmic scale.

It's interesting to reverse the Vermeulen calculation and graph total testosterone as a function of free testosterone (SHBG = 30 nMol/L, albumin = 4.3 g/dL):
View attachment 21599
Look familiar?

On a linear scale, and including data to the origin:
View attachment 21601

Very nice! Thank you.