Letro myths ??

[brutale]

Many bros believe that letro positively annihilates estrogen, reducing E2 by as much as 90%. I certainly accepted that idea.

But I just saw two studies in healthy men of various ages which would contradict this notion. The estrogen reductions were much more modest: 46-62%. And at 2.5mg/day. (And w/o a half gram of test!)

Here is one study:
Comparative Assessment in Young and Elderly Men of the Gonadotropin Response to Aromatase Inhibition -- T’Sjoen et al. 90 (10): 5717 -- Journal of Clinical Endocrinology & Metabolism

and I saw another that was similar. I think it is important that we are talking about results in men, not women.

I guess I'm wondering whether peoples' labs are really showing E2s of <15 on letro, or whether we need to change our idea that we can easily drive E2 to near zero on letro.

So, that begs the question: if studies are right and letro lowers E2 only 50%, why are so many people having libido issues? Is it definitely via Letro's estrogen reduction or is something else at work? ... Confusing

 

[tpd01883]

This is very interesting. I have always accepted that letrozole was stronger than adex and aromasin... However if these studies are true it doesn't appear to be much stronger. I believe that at doses less than 2.5mg adex shows similar drops in e2. This makes me wonder if letrozole's ability to reverse gyno is from something other than extremely low e2 levels... Perhaps some sort of receptor mediated gene expression reversal via antagonism like a serm might do.

 

[-Z-]

Thanks for the link, bro.

Some good info here

 

[brutale]

Looking more carefully at the studies, it seems like the following statements are true:
- in healthy males, a-dex at 1mg per day can be expected to lower E2 by about 25% (with considerable individual variation)
**broken link removed**
- aromasin 25mg. comes in around 30%
- letro 2.5mg around 50%

So, letro produces the largest average declines, and can take E2 from, say, 20 to 10 in healthy men. (I'm not sure what this means for someone on an aromatizable cycle who might be running E2 @ 60+ without an AI. Probably letro does the most, but one would think that it is unlikely to crush E2 to single digits.)

I'm pretty E sensitive - so I'm giving letro a try at 0.25 a day (against some test-e). So far it "feels" pretty strong, about like 12.5 of aromasin, maybe stronger ... but nothing crazy so far.

 

[Newman]

Interesting thread. Always good to get new info, particularly when it may correct previous misconceptions.

 

[Anafit]

The myth about Letro is in every gym in the world. Thousand of steroid users will even tell you that it eliminates or drops E2 levels to where it inhibits your gains. And on the internet you can find people posting that AI's inhibit your gains all over, even here.
As you've found, that's just not true. There is plenty of E2 left in you even with AI use. Also, those studies are not done on men, on steroids. On cycle your T levels are an average of 7 times higher than normal. So that means your E2 levels will be raised as the T gets converted. If you cut 50% of the E2 on cycle you'll still have 3-5 times the normal level.

 

[plang]

Why does it matter what percent of estrogen it lowers? It still is the strongest AI...and estrogen plays many roles in the body...some I'm sure unknown to us at this point....letrozole kills my libido and erections...even at 2.5mgs eod....50%....90%.....i will stick to arimidex or aromasin unless it's the last 2 weeks precontest....i don't even use an AI unless I'm running more than a gram (which i did once) and when using letro it zapped my sex drive and libido even at 1.5g of test....and my gf is pretty hot

 

[brutale]

complicated stuff

There's no denying the experiences of a lot of people: letro can cause libido problems. "Hindering gains" may be harder to assess but we do have a potential mechanism: lower igf-1 after AI use.

The libido thing is real no doubt, but harder (for me) to understand in terms of E2 suppression. First, letro at high doses suppresses only half the estradiol in men not even on cycle, for ex. 25 to 12. To be sure, 12 is sub-normal. Second, for guys on cycle (w aromatizable gear), letro would be unlikely to take E2 to even that level. More realistically, E2 might go from 80 to 30 or something. (You might have guessed that libido could improve ... too much estrogen can suppress libido, and one study showed letro improved libido in guys with high E due to anti-viral treatment.) Third, several people have reported that adding proviron (!) helped resolve letro-induced libido loss. If the issue is rock-bottom E2, adding proviron shouldn't help, should it? DHEA or straight estro might though.

My take-away is that the libido issue is pretty subtle (does it depend on a bunch of ratios among dht, t, and E?) and letro mayp doing more than just lowering E.

 

[Anafit]

E2 controls your erection. Dropping levels quickly will have a negative affect. Once your body gets used to the level it'll balance out and your erection will return. In the mean time, use clomid to substitute the missing estrogen. That'll do it. HCG if you have it as well.

 

[Mad Matt]

Have you noticed there was a washout period????