Kindke has an interesting post on an easy way to increase testosterone, through inhibiting the enzyme aromatase. This enzyme is responsible for converting testosterone (T) into estradiol. In the study Kindke linked, T increased as much as 60% in healthy young men with normal T levels. That’s pretty good. See charts below.
I looked for some other studies. Just so we can see whether the same effects hold in older men with low T, look at this one: Effects of Aromatase Inhibition in Elderly Men with Low or Borderline-Low Serum Testosterone Levels.
As men age, serum testosterone levels decrease, a factor that may contribute to some aspects of age-related physiological deterioration. Although androgen replacement has been shown to have beneficial effects in frankly hypogonadal men, its use in elderly men with borderline hypogonadism is controversial. Furthermore, current testosterone replacement methods have important limitations.
We investigated the ability of the orally administered aromatase inhibitor, anastrozole, to increase endogenous testosterone production in 37 elderly men (aged 62–74 yr) with screening serum testosterone levels less than 350 ng/dl. Subjects were randomized in a double-blind fashion to the following 12-wk oral regimens: group 1: anastrozole 1 mg daily (n = 12); group 2: anastrozole 1 mg twice weekly (n = 11); and group 3: placebo daily (n = 14). Hormone levels, quality of life (MOS Short-Form Health Survey), sexual function (International Index of Erectile Function), benign prostate hyperplasia severity (American Urological Association Symptom Index Score), prostate-specific antigen, and measures of safety were compared among groups.
Mean ± SD bioavailable testosterone increased from 99 ± 31 to 207 ± 65 ng/dl in group 1 and from 115 ± 37 to 178 ± 55 ng/dl in group 2 (P < 0.001 vs. placebo for both groups and P = 0.054 group 1 vs. group 2). Total testosterone levels increased from 343 ± 61 to 572 ± 139 ng/dl in group 1 and from 397 ± 106 to 520 ± 91 ng/dl in group 2 (P < 0.001 vs. placebo for both groups and P = 0.012 group 1 vs. group 2). Serum estradiol levels decreased from 26 ± 8 to 17 ± 6 pg/ml in group 1 and from 27 ± 8 to 17 ± 5 pg/ml in group 2 (P < 0.001 vs. placebo for both groups and P = NS group 1 vs. group 2). Serum LH levels increased from 5.1 ± 4.8 to 7.9 ± 6.5 U/liter and from 4.1 ± 1.6 to 7.2 ± 2.8 U/liter in groups 1 and 2, respectively (P = 0.007 group 1 vs. placebo, P = 0.003 group 2 vs. placebo, and P = NS group 1 vs. group 2). Scores for hematocrit, MOS Short-Form Health Survey, International Index of Erectile Function, and American Urological Association Symptom Index Score did not change. Serum prostate-specific antigen levels increased in group 2 only (1.7 ± 1.0 to 2.2 ± 1.5 ng/ml, P = 0.031, compared with placebo). These data demonstrate that aromatase inhibition increases serum bioavailable and total testosterone levels to the youthful normal range in older men with mild hypogonadism. Serum estradiol levels decrease modestly but remain within the normal male range. The physiological consequences of these changes remain to be determined.
The older men in this study had a huge increase in T, more than double the level of free T in one group. These are very worthwhile results, comparable (I believe) to actual T supplementation.
So, aromatase inhibitors work in both young, normal T level, and older, abnormal T level, men. Notable is that the aromatase inhibitor mentioned above, anastrozole, is now generic and fairly cheap. Don’t know if it can be had from overseas pharmacies.
Also, I posted the other day that resveratrol increases sperm counts and T levels in rats. The mechanism might very well be aromatase inhibition: The red wine polyphenol resveratrol displays bilevel inhibition on aromatase in breast cancer cells.
Don’t know what if any downside aromatase inhibitors have. It seems a whole lot easier to take them than to use injectable T or any other kind.