Letrozole is an aromatase inhibitor. One of the most powerful aromatase inhibitors available today. Far too many people are considering this method because many moons ago it was touted as a good tool for reversal. We've learned a lot since then and Selective Estrogen Receptor Modulators (SERM) studies on gynecomastia reversal are readily available for confirmation.
I did a short experiment myself recently when my E2 came back at 46 pg/mL (Range < 29 for a sensitive E2 assay). I did not experience gynecomastia, but I wanted to bring that down back to range. The increase was likely due to switching my Testosterone Therapy administrations from subcutaneous (SubQ) to intramuscular (IM). IM injections have more of an impact on E2 due to faster absorption. This result came about on July 2nd. I had a Letrozole prescription laying around and figured I'd give it a go. It's been so long since I've used Letrozole. My prescription was for 100 microgram capsules.
I administered 100 mcg. (Micrograms) daily. After the 10th day I felt miserable and so I discontinued use. One week
after I stopped, I tested E2 again and it came back 2 pg/mL. Remember, this is a full week after Letrozole was discontinued. So it had to be at zero, or "too low to count" for several days. I was bedridden for several days. Completely useless and couldn't find a reason to get up and about. If you've killed your E2 before, you know exactly what I mean. I don't wish this on anyone. Really amazes me that some folks are running this thing using milligram after milligram several times per week. And these "Gynecomastia Reversal" threads using these astronomical doses are just mind boggling. Pretty eye opening once again. Anyway, I waited a while and got back on DIM.
The entire letrozole for gynecomastia reversal came about in 2001 when a study was published. This study was done on mice, not humans. So don't be a mouse, be a man.
PMID: 11850204 if you want to look it up.
To give you an example of how low this drug is supposed to be dosed, it was studied in extremely obese hypogonadal men. Overweight men convert far more estrogen than non-overweight men. This is because they carry far more aromatase enzymes. Using Letrozole, these highly aromatizing men were treated with doses of 2mg to 2.5mg once per week. If we break that up, you're looking at about 285 micrograms per day. That's it. This powerful drug never, under any circumstances should be used in a milligram + basis on a daily administered protocol. It is simply outrageous.
Reference here.
Let's look at some more recent studies:
Dated: 2011 -
Effects of aromatase inhibition on male breast
Tamoxifen was much more effective, however, in the prevention of gynecomastia in these men. Due to these disappointing results,
aromatase inhibitors are not recommended as a first-line treatment for gynecomastia in men.
^ Click here for the source of the excerpt above.
Dated: 2004 -
Beneficial effects of raloxifene and tamoxifen in the treatment of pubertal gynecomastia
Inhibition of estrogen receptor action in the breast appears to be safe and effective in reducing persistent pubertal gynecomastia, with a better response to raloxifene than to tamoxifen.
No side effects were seen in any patients.
^ Click here for the source of the excerpt above.
Dated: 2004 -
Management of physiological gynaecomastia with tamoxifen
Thirty-six men accepted tamoxifen for physiological gynaecomastia. They were offered oral tamoxifen 20mg once daily for 6-12 weeks. Oral
tamoxifen is an effective treatment for physiological gynaecomastia, especially for the lump type.
^ Click here for the source of the excerpt above.
So we've learned a couple things here. We know that an Aromatase Inhibitor is a poor choice, and we also learned that SERM's are more effective, safer and with no side effects. Lastly, we learned that while Tamoxifen is effective, it is superseded by the superior SERM; Raloxifene.
Aromatase inhibitors are not selective and will demolish your estradiol levels with prolonged use, rendering you miserable and useless. In the case of Letrozole, you could deplete your E2 levels to nothing in no time. SERMs like Tamoxifen and Raloxifene are pure antagonist in the E receptor in breast tissue. This is what mainly makes a SERM the clinically preferred drug for gynecomastia reversal.
TO REVERSE GYNECOMASTIA WITH SERMS:
Raloxifene: 60mg daily. You should see improvement in approx. 4 to 6 weeks. If not increase by 20 mg for every 3 weeks, never to exceed 100mg daily. (If you're deficient in calcium, vitamin D or calcitonin, or if you're concerned with bone demineralization, use 60mg daily for 10 days then 30m daily until reversed).
Tamoxifen: 40mg daily for once week. Then 20mg daily until gynecomastia is reversed.
Both protocols above will take time. This is not a 2 week process. Reversal will require patience. But it most certainly is effective, side-effect-free and cost incredibly effective when compared to surgery.