Human spermatogenesis requires both FSH and micromolar (µM) locally-secreted intratesticular paracrine T

madman

Super Moderator




Male HPG axis
1765126713545.webp






Human spermatogenesis requires both FSH and µmolar locally-secreted intratesticular paracrine T

- 100X serum concentration is normal

- 10-20X serum will do and is achievable with hCG 500 iU 2-3X/week


Can't be sustained by µmolar nmolar circulating endocrine T



1765126821187.webp

1765126841780.webp
 
Cells of the testis
1765128224410.webp

1765128250934.webp





Exogenous androgens in the system (exogenous T)

- shutdown of LH/FSH secretion

- even though we increase levels of testosterone in circulation we actually cause levels in the testes to collapse and also spermatogenesis likewise collapses


1765128335498.webp

1765128348274.webp
 
 
 
Just as a data point, I did over 12 years with literally no break on therapeutic dosages of testosterone with periodic peptides, Hcg, etc., with 0 FSH and 0 LH for a significant period of time… At least a decade, and after a painful coming off period of 2-3 months My LH and FSH are now well up into the normal range, so now I am seeing whether my testosterone and swimmers will follow suit. Just got my latest lab.
 
Just as a data point, I did over 12 years with literally no break on therapeutic dosages of testosterone with periodic peptides, Hcg, etc., with 0 FSH and 0 LH for a significant period of time… At least a decade, and after a painful coming off period of 2-3 months My LH and FSH are now well up into the normal range, so now I am seeing whether my testosterone and swimmers will follow suit. Just got my latest lab.

Did you have an SA done pre-TTh?

Chances are at your age especially being on exogenous T for over a decade your baseline T will not be stellar.

Hard to say where your sperm parameters sit but keep in mind endogenous T will recover back to baseline much sooner than sperm parameters.

With gonadotropin therapy it can be anywhere from 3-6 months or in many cases longer if stopping cold turkey.
 
Oh man. Happy to share, but what is SA? And what is TTH? I’m thinking about sprinkling in some clomiphene citrate and hcg since basically at this point, I have secondary hypogonadism, but agreed that I really have no idea how long it will take if ever. Frankly, I don’t feel as awful as I thought I would even though 250 total and even farther below normal range on free should be pretty miserable.
 
Oh man. Happy to share, but what is SA? And what is TTH? I’m thinking about sprinkling in some clomiphene citrate and hcg since basically at this point, I have secondary hypogonadism, but agreed that I really have no idea how long it will take if ever. Frankly, I don’t feel as awful as I thought I would even though 250 total and even farther below normal range on free should be pretty miserable.

Semen analysis.

Testosterone therapy.

Your TT 250 ng/dL is dismal and the critical fraction FT would be in the gutter if you had normal SHBG or fall in the grey zone if you had very low SHBG.

Standardized/harmonized reference range for TT 264-916 ng/dL and your hitting 250!
 
I was off the chart semen analysis for years, and then went to zero probably for the last six years, so we will see if it comes back or not. Luckily, I banked a bunch just in case because I knew the risk of long-term therapeutic testosterone replacement therapy.

Ironically, 250 was roughly what I was before starting therapy 15+ years ago, but I do not remember what my free was. I have the old lab tests because I have always saved those things. I will try to look it up for my next update here.
 

hCG Mixing Calculator

HCG Mixing Protocol Calculator

TRT Hormone Predictor Widget

TRT Hormone Predictor

Predict estradiol, DHT, and free testosterone levels based on total testosterone

⚠️ Medical Disclaimer

This tool provides predictions based on statistical models and should NOT replace professional medical advice. Always consult with your healthcare provider before making any changes to your TRT protocol.

ℹ️ Input Parameters

Normal range: 300-1000 ng/dL

Predicted Hormone Levels

Enter your total testosterone value to see predictions

Results will appear here after calculation

Understanding Your Hormones

Estradiol (E2)

A form of estrogen produced from testosterone. Important for bone health, mood, and libido. Too high can cause side effects; too low can affect well-being.

DHT

Dihydrotestosterone is a potent androgen derived from testosterone. Affects hair growth, prostate health, and masculinization effects.

Free Testosterone

The biologically active form of testosterone not bound to proteins. Directly available for cellular uptake and biological effects.

Scientific Reference

Lakshman KM, Kaplan B, Travison TG, Basaria S, Knapp PE, Singh AB, LaValley MP, Mazer NA, Bhasin S. The effects of injected testosterone dose and age on the conversion of testosterone to estradiol and dihydrotestosterone in young and older men. J Clin Endocrinol Metab. 2010 Aug;95(8):3955-64.

DOI: 10.1210/jc.2010-0102 | PMID: 20534765 | PMCID: PMC2913038

Online statistics

Members online
3
Guests online
221
Total visitors
224

Latest posts

Beyond Testosterone Podcast

Back
Top