HRT patients are on as little as 50mg a week (or 100mg every two weeks), or as much as 200mg a week. This depends on how flexible thier TRT (HRT) doctor is, and where the patient wants to come out in thier blood tests, 300ng or 1000ng etc, which also depends on thier own genetics as well as dose administered.
Also keep in mind, an esterified testosterone as opposed to raw suspension is not going to be 100mg testosterone in 100mg suspended substance.
These numbers are equivalent to percentages total test
Ester actual mg/100mg dose
test no ester 100
tren acetate 87
test prop 83
test enanth 72
test cyp 70
test undecan 63
These numbers are not 100% accurate either as laboratories are subject to small errors or loss in conversion.
By the way, I have seen a couple young 20 year olds testing in the low to mid 200s, so dont think that age means everything because it doesn't.