[quote]Mr. Walkway wrote:
[quote]drunkpig wrote:
[quote]Mr. Walkway wrote:
This is not true. They all reduce free estrogen in young males by about 45-50%.[/quote]
You are partially correct. I got my order mixed up. exemestane is the most potent, followed by letro and adex.
Using William Llewellen’s AAS reference manual it seems that, in clinical trials, adex and letro suppressed around 75-80% of estrogen. Armoasin (exemestane) was at 85%.
To quote Llewellen himself, “Aromasin may perhaps be the most effective aromatase inhibitor to date”.
If you want to argue with Bill, go ahead.
[/quote]
my mistake, I meant 45-60% in young males, and about the same in elderly ones… It really depends on what they use
Abstract
Context: Aging in men is associated with a decline in serum testosterone (T) levels.
Objective: Our objective was to assess whether decreased T in aging might result from increased estradiol (E2) negative feedback on gonadotropin secretion.
Design and Setting: We conducted a comparative intervention study (2004) in the Outpatient Endocrinology Clinic, Ghent University Hospital.
Participants: Participants included healthy young and elderly men (n = 10 vs. 10).
Interventions: We used placebo and letrozole (2.5 mg/d) for 28 d, separated by 2 wk washout.
Main Outcome Measures: We assessed changes in serum levels of free E2, LH, and FSH, free T, SHBG, and gonadotropins response to an iv 2.5-�??�??�?�¼g GnRH bolus.
Results: As assessed after 28 d of treatment, letrozole lowered E2 by 46% in the young men (P = 0.002) and 62% in the elderly men (P < 0.001).
In both age groups, letrozole, but not placebo, significantly increased LH levels (339 and 323% in the young and the elderly, respectively) and T (146 and 99%, respectively) (P value of young vs. elderly was not significant). Under letrozole, peak LH response to GnRH was 152 and 52% increase from baseline in young and older men, respectively (P = 0.01).
Conclusions: Aromatase inhibition markedly increased basal LH and T levels and the LH response to GnRH in both young and elderly men. The observation of similar to greater LH responses in the young compared with the elderly does not support the hypothesis that increased restraining of LH secretion by endogenous estrogens is instrumental in age-related decline of Leydig cell function.
im fine with disagreeing with William on this… clinical trials back me up. I wouldn’t call Op “elderly”… but that’s just me
The trials that were conducted that say that aromasin lowers estrogen by 80%+ and letro by 95%+ were performed on post menopausal women who… do not really have much aromatase floating around…[/quote]
That’s for patients NOT on TRT, though, so the HPTA compensates somewhat.
For patients on TRT, whose HPTA is shut down, one would expect a bigger effect for the same AI dose.