Created by mussDR | Reviewed by Marco
Below are tables of literature on Testosterone pharmacokinetics and related serum levels.
This is a work-in-progress article and project.
I offically reviewed all the studies listed below but I still need to add information on how to interept the data.
However, I've listed excerpts from mussDR below that should be incredibly helpful.
Female regulation of sex hormones is incredibly complex and does not replicate that of a males. These values are only given to make it clear, which dosages will usually provide suppression and which will fail in all cases.
I see a lot of people telling late teens and even adults to take 50mg and literally 25mg.
Those are not typical doses and will result in low testosterone levels for a male.
To avoid portraying dosage absolutism either, let's look into titrated regimens where dose is optimized based on blood test results.
Only ±42 patients needed to reduce their dosage to 50mg while ±221 stayed on 75/100mg.
More people were titrated up to 100mg than decreased to 50mg.
Note: Those studies also used 350-650 ng/dL trough as a target range, which is low for us.
Aromatase function is present regardless of dosage and whether you are on testosterone or not.
As you can see doses up to 125mg a week are not associated with significant aromatization.
There are studies with even higher doses showing that but they're not presented here.
“I'm taking 60mg and in my last blood test estradiol came back 70 pg/mL, is my T too high so it started to aromatize?”
Still, that's where a strict burden should be drawn.
If you take a low dose, you will eventually have high estradiol levels because the primary source of estrogen in females is not peripheral aromatization but a gonadal secretion, which we want to be suppressed.
Transgender boys and men are not more androgen-sensitive than average males
[1]
[2]
[2.1]
.
Furthermore, as our goal is to make treatment efficient, we should understand that we need a typically higher dose to achieve this.
That arises from estrogen production that comes along with female puberty, we need to suppress the most potent and predominant steroid hormone - Estradiol.
For example, although this study [3] used Testosterone Undecanoate, it still supports the tendency for requiring a higher dosage.
Note, transgender patients also had higher dose per BSA than non-transgender patients.
"The present findings demonstrate that after individual dose titration,
serum LH and FSH are markedly less suppressible in trans men compared with men with primary or secondary hypogonadism despite a higher dose in microgram per square meter."
Weight also plays lot of significance as majority of transgender men weigh less than average healthy men.
They might expect particularly higher serum levels for this reason.
For example, 62kg (137lb) individual would have around 25% slower clearance rate while having around 43% less volume of distribution which can even go up to 65%,
if compared to a 85kg (187lb) control [4].
Conversely, individuals with higher body weight statistically require bigger doses.
However, don't interpret it like: If person X weighs 62kg (137lb) and person Y weighs 74kg (163lb), dose should be calculated by difference in kg.
Please ignore this table if you're looking for non-titrated data.
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