Testosterone Conversions mg->ng/dl?

[James23]

Testosterone is normally measured in nanograms per deciliter (ng/dL.)

Normally functioning adult male testicles produce an average of 7mg of testosterone per day,

1 milligram = 1,000,000 nanograms
1 liter = 10 deciliter

There are 5 liters of blood in the average adult male body.

This means that the average male "total testosterone" output into the bloodstream is:

7,000,000ng / 50 dL = 140,000 ng / dL total testerone per day.

Therefore, using an often accepted 800ng/dL "reference" measurement for "optimal" testosterone, it could be proven that the assay is revealing 1/175th of the total daily testosterone output.

Further, this means that in the theoretical model of the optimal male described above, the total point-in-time reading of 800mg/dL of testosterone is completely metabolized by the body 175 times per day.

800ng/dL in a 5L volume of blood is equivalent to:

800 ng / 1 dL = 40,000 ng / 50 dL = .04 mg / 5L = 0.04mg total testosterone in the bloodstream. at the time of assay.

0.04mg * 175 cycles = 7mg total testosterone produced by the testicles per day.

Testosterone metabolism appears to be quite rapid! Thoughts? Problems with the math?

 

[Conciliator]

Testosterone metabolism appears to be quite rapid!

Right. If you assume the body is producing 7mg per day, yet levels in the body remain relatively stable, then there must be about 7mg per day that's being metabolized.

Test is obviously 5-alpha-reduced to DHT and aromatized to estrogen, but I believe the primary fate of testostone is hepatic breakdown to androsterone or etiocholanolone, which are then excreted in the urine.

 

[James23]

Also, for those that wish to visualize the amount of testosterone that is produced, in total, by the testes by the average "optimal" male: imagine 7/1000ths of a drop of water from a milliliter eyedropper.

To visualize the amount of testosterone in your blood at any one time, imagine 1/250,000th of a drop from an eyedropper.

To produce 1 eyedropper drop (1ml) of testosterone in total, it takes the average pair of testicles approximately:

143 days, or 5 months, or 20 weeks.

Quite a contrast from from the imagery provided in common literature describing testosterone.

 

[Conciliator]

Also, for those that wish to visualize the amount of testosterone that is produced, in total, by the testes by the average "optimal" male: imagine 7/1000ths of a drop of water from a milliliter eyedropper.

To visualize the amount of testosterone in your blood at any one time, imagine 1/250,000th of a drop from an eyedropper.

To produce 1 eyedropper drop (1ml) of testosterone in total, it takes the average pair of testicles approximately:

143 days, or 5 months, or 20 weeks.

Quite a contrast from from the imagery provided in common literature describing testosterone.

Your're overstating the size of a drop of water. 1 ml is quite a bit more than a drop. Think of all the water in a 1 ml insulin syringe. While all that water weighs 1g, a drop of water is much, much lighter. For example, http://209.85.173.132/search?q=cache:VGRHmcwB3_kJ:www.public.asu.edu/~rudenun/chm113/lab1/report.doc+table+1+volume+and+mass+measurements+of+water&cd=1&hl=en&ct=clnk&gl=us (this page) states a drop of water weighs 25mg and this experiment calculated it to be 43 mg.

So to visualize the amount of testosterone that's produced per day, you're not looking at 7/1000 of a drop of water. You're looking at something like 1/3 of a drop of water to 1/7 of a drop of water.