Book correction · September 2026
The numbers are right.
The unit was wrong.
A reader caught a real error in Mastering TRT. Here is the correction, the conversion, and how to get the updated edition.
What changed
In the section on target free testosterone levels, the values are printed with the wrong unit. The numbers themselves are the ones I use with my own patients. The label next to them is not.
What the book says
100–200 ng/dL
Read literally, that is several times above the top of any normal free testosterone range. It was never the intent.
What it should say
100–200 pg/mL= 10–20 ng/dL
Every free testosterone target and case value in that chapter is a pg/mL figure. Read that way, they line up with standard lab ranges.
The corrected editions print both units at every target, so it cannot be misread again.
Check your own labs
Labs do not agree on units for free testosterone. LabCorp typically reports pg/mL. Some Quest panels report ng/dL. They differ by a factor of ten.
1 ng/dL = 10 pg/mL
To go from pg/mL to ng/dL, divide by 10.
150 pg/mL ÷ 10 = 15 ng/dL.
Check which unit your report uses before comparing it to any target. A result of 360 pg/mL and a result of 36 ng/dL are the same number.
What was not affected
- Total testosterone figures are correct as printed. Those genuinely are ng/dL.
- Estradiol (pg/mL), PSA (ng/mL), SHBG (nmol/L) and cortisol (mcg/dL) values are all correct.
- The dosing, timing, estrogen management, side effect content, etc. is unchanged. Only the unit label on free testosterone was wrong.
Getting the corrected edition
| Format | How to update |
|---|---|
| Kindle | On Amazon, open Manage Your Content and Devices → Books, find the title, and choose Update Available if it is shown. If it is not, delete the book from your device and re-download it. That pulls the current version. |
| Audible | Remove the title from your device and re-download it from your Audible library. The narration is regenerated from the corrected text. |
| Paperback | Printed copies cannot be updated, and you do not need a new one. The correction is entirely above: read every free testosterone figure in that chapter as pg/mL, with a target of 100–200 pg/mL (10–20 ng/dL). Nothing else in the book changes. |
This page fixes one number.
The book tells you what to do with it.
Knowing the target is 100–200 pg/mL does not tell you where you should sit in that range, or what to do if you are outside it. That is what the book covers.
- How to set your own target from age and symptoms. Under 40 is not the same as over 65.
- Why the timing of your blood draw relative to your last injection changes the number, and how to read a peak draw against a trough draw.
- What high or low SHBG does to your free testosterone, and why total testosterone alone misleads you.
- Why pushing past roughly 240 pg/mL usually makes things worse instead of better.
- How estradiol and hematocrit have to be managed alongside testosterone, with the dosing protocols to do it.
If you are on TRT and trying to read your own labs, that is the part you need.
Get Mastering TRT Try the Lab Analyzer
Thank you to the reader who spotted this. It is exactly the kind of catch that makes a book better.
This page is a publishing correction, not medical advice. Testosterone targets vary by person, assay and clinical picture. Interpret your labs with the clinician managing your treatment. Dr. Robin Terranella is a board-certified naturopathic physician at Southwest Integrative Medicine in Phoenix, Arizona.