T Nation

Studies on Blood Concentration of Testosterone by Hour by Type


Thanks, first, to everyone who contributes to this forum and provides so much information.

I am on TRT. I would like to know more about the rise and fall of testosterone, free testosterone, and estradiol by day and hour with different treatment regimens.

I am familiar with the various treatment regimens practiced, but I'd like to look at something more clinical and precise. Does anyone know of a study or studies that show how blood levels of T, Free T, and E2 change after

1) Test injections of different quantities and types (enanthate, cypionate) (by hour/day)
2) Application of transdermals )Testim/Androgel




"2) Application of transdermals )Testim/Androgel"

I used Androgel for nine years, have been using Testim for the past month, and finally got authorization through insurance to have Testopel. I'm getting the Testopel implanted this month.

(Androgel was drying my skin out this winter for some odd reason and Testim has a better emollient [pentadecalactone]).

Get the product literature for Testim and Androgel and you'll be provided with the information you want. Testim takes two hours to absorb and usually gives a higher level of T because of its emollient. Androgel takes about six hours to get fully absorbed.

"1) Test injections of different quantities and types (enanthate, cypionate) (by hour/day)"

Use Med Line or any other peer reviewed work on these drugs. I have a very good article attached on this forum discussing all modalities of T replacement and it goes over this.

Why you want to know hour by hour is beyond me.

I like this forum and have nothing bad to say about it, but you're basically going to read the SAME THING from every poster who comes in here:

1) Read the stickies.
2) Use a long lasting T at 50 mg every other day, plus HCG and Arimidex.
3) Transdermals and pellets suck (which is NOT the case for me and quite a few others on this board and thousands and thousands of men who have success with these forms of TRT).


Thanks for your reply.

I've read through the stickies, and I'm familiar with the forum consensus (inject 100mg/week in at least two or more injections per week).

I'm interested in the hour by hours/day by days of concentrations for two reasons:

1) Timing of blood work
2) Making a persuasive argument to an endocrinologist about multiple injections weekly




1) I don't see the point in trying to get a perfect timing of blood work. If you feel good and you're in the normal range, why would hour by hour readings even matter? Would it make a difference that your lab value is 600 ng/dl some time and 800 another? I've tested between 600 to 1000 on 10 grams of Androgel for all these years. Why would I care about fluctuations in T values when all of them have me feeling good and are in the mid to high normal range?

2)If you have to persuade an endocrinologist, don't you think s/he isn't competent in TRT? I'd actually afraid to seek medical attention from someone I need to persuade. Just the fact that I have to convince or persuade means I'm dealing with someone who's not up to speed and incompetent in this area. This is why I see a urologist with a fellowship in andrology; I think you should do the same. Actually, if one has a competent doctor (like me), they don't read stickies and follow medical advice from non-doctors

One hundred mg twice or more times per week is not a clinical dosage. That is sure to cause problems, and is considered abuse.


Here's the paper: http://www.aace.com/pub/pdf/guidelines/hypogonadism.pdf



The following study (Clinical Use and Abuse of Androgens by Matsumoto) had a lot of what I was looking for:


Thanks also for your words of advice. Perhaps my initial post may have been unclear: I meant to say that the forum's recommendation was 100 mg testosterone enanthate per week, divided into doses (with a total of 100 mg/week). I believe that this is precisely the dosage recommended by various endocrinologists for the purposes of TRT.


Yup - 100 mg per week is the dose for injections.


100mg of test ester yields roughly 70mg of T, bioidentical T. That is around 10mg/day, close to the production of a young virile male. The 100mg dose does seem arbitrary at first.

If one doses T, hCG and anastrozole EOD, levels will not be changing much at all. Thus little concern for lab timing effects.


Thanks for your responses, gentlemen. Good to know.