+ 7 Some Misconceptions about the use of Letrozolo and other AI's
I've been seeing a high incidence of estradiol E2 levels through the roof in looking at
labs. Why is that. We have the tools to counter this so I asked my self why. Why are we
not using them. I think it comes down to fear. Fear that you may drop your estrogen
levels to low. In reading posts on here I keep reading about how letro is bad to use as
an AI. The reasons stated are that it can surpress estrogen by 98%. I want to clarify
this. It is a partial truth. That number is based on a study of women. You see Letrozole is
used to treat breast cancer in postmenopausal women. So the medical studies were
mostly based on women. In women letro has been shown to supresses estro 98%. Letrozole
has also been used for ovarian stimulation by fertility doctors since 2001 because
it has fewer side-effects than clomifene (Clomid) and less chance of multiple gestation.
Again women.
Most know that Letrozole is used as a treatment for gynecomastia, although it is probably
most effective at this if caught in an early stage (such as in users of anabolic
steroids) Now here we go men use it. What I post here is from a published Medical Study
on men. It shows that letro acts a little differently in men as far as how much estrogen
it suppresses.This will also explain how estrogen is produced in the body to help
understand how to counter it not only with Letro,but other AI's.
Aromatase, also known as estrogen synthetase, is the key enzyme in estrogen biosynthesis.
Transcription of the aromatase gene is regulated by several tissue-specific promoters.
Aromatase activity has not only been demonstrated in gonads and placenta but also in brain,
fat tissue,muscle,hair,bone,and vascular tissue.
Estradiol E2 is the most potent estrogen produced in the body. It is synthesized from
testosterone or estrone E1 via aromatase or 17β-hydroxysteroid dehydrogenase, respectively.
The total estradiol E2 production rate in the human male has been estimated to be 35-45 μg (μg=mcg)
(0.130-0.165 μmol) per day, of which approximately 20% is directly produced by the testes.
Roughly 60% of circulating estradiol E2 is derived from direct testicular secretion or from
conversion of testicular androgens. The remaining fraction is derived from peripheral
conversion of adrenal androgens. The mean estradiol E2 plasma concentration in men is only
about 1/200 of the mean plasma testosterone concentration and is comparable to estradiol
levels found in women in the early follicular phase of the menstrual cycle.
Aromatase inhibitors are classified as either steroidal or nonsteroidal, or as first,
second or third generation. Steroidal inhibitors such as formestane and exemestane inhibit
aromatase activity by mimicking the substrate androstenedione. Nonsteroidal enzyme
inhibitors such as anastrozole and letrozole inhibit enzyme activity by binding with
the heme iron of the enzyme. Third-generation inhibitors such as letrozole and anastrozole
are potent and do not inhibit related steroidogenic enzymes like first-generation AI's did.
They are well tolerated and apart from their effects on estrogen metabolism their use does
not appear to be associated with important side effects in postmenopausal women.
Although aromatase inhibition by anastrozole and letrozole is reported to be close to 100%,
administration of these inhibitors to men will not suppress plasma estradiol levels completely.
In men third-generation aromatase inhibitors will decrease the mean plasma estradiol/testosterone
ratio by 77%.This finding probably relates to the high plasma concentrations of testosterone,
a major precursor for estradiol synthesis in adult men. As aromatase inhibition is dose dependent
it has been suggested that aromatase is less suppressed in the testis compared to adipose and muscle
tissue, explaining the incomplete efficacy of aromatase inhibition in men. Aromatase activity is high
in the testes and the molar ratio of testosterone to letrozole is much higher in the testes compared
with adipose and muscle tissue. When testicular testosterone and estradiol synthesis are suppressed
and testosterone is administered exogenously in combination with letrozole, however, the
estradiol/testosterone ratio is suppressed by 81%,which is only marginally different from the
suppression of this ratio in intact men after treatment with letrozole. This incomplete
suppression may be regarded as advantageous for it prevents excessive reduction of estrogen
levels in men and the possible associated adverse effects.
You can find the complete study here. As always let me know what you think.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3143915/
http://www.ncbi.nlm.nih.gov/pubmed/23103016
http://www.ncbi.nlm.nih.gov/pubmed/17940445
http://www.eroids.com/pics/updatedlab-reports-102-testosterone-how-to-pr...
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This thread is a year old. I bumped it cuz Im studying ais and hoping for a gathered consensus. From what Im reading, aromasin seems to be the best ai, but Im not sure and want to know what the vets think as far as is something better for different compounds? The best Ive read so far is from a banned member, but its still a stickie...
http://www.eroids.com/forum/steroids-qa/pct-anti-estrogens/pct-and-aromasin
You'll find varying opinions. It's all in how your body reacts to each one. I would suggest getting both start with the one you want to try and see how it goes. If you think you are having bad results or not reacting well to it then switch to the other. Just make sure you understand the dosing protocols for each as they are different. It's all trial and error. Adex and Aro are for compounds that will covert to estrogen. 19-nors require prolactin control. As you know, it's best to make a first run with Test.
But here recently it has been shown that if you can keep estrogen in check that prolactin won't even be an issue. In my case I and this is only in my case. I keep my estrogen in check and I have to very little prolactin blocker. I want to express for the new guys that this is ONLY in my case this may not be the same for all.
This is true. Comes down to estrogen control, but still have something on hand in case. Better safe than sorry.
Agreed always have your prolactin control on hand.
Thank you brother, the trial and error process is what I was leaning toward cuz I plan to do test only cycles for awhile anyway. The only probs with that are that I dont wanna waste $ or time and dont know if what works with test only will work the same with added compounds. Researching tho and workin on it.
RustycanHey bro I'm pretty new to this whole AI thing after reading your entire thread I'm a little confused as to what your point is about Letro and the others. Are you saying Letro is no good, better or was the post just saying how it works in general?
From what ive read most people use aromasin and adex for estro control. And people mainly use letro for minor gyno flares. It can reduce it or cure (I say that cautiously) it if used quickly and not let go out of control.
Their plenty to read if you use the search feature, thats were I go for info. Its like a gear encyclopedia, I love that magnify glass thing!
RustycanThat's simplified enough for my brain......I think lol. Thank you sir you are a gentleman and a scholar
I love that magnifying glass too! Sometines it gets frustrating tho cuz the pooter dont know what Im lookin for and keywords and combos can send you right past what you wanna see.
Type "tits" and see what you get bro.............................. every gyno post EVER!!
Gotta bump this. Need the help and current feedback.
When it comes to this comparison of AIs its more about type of estrogen suppression as opposed to "strength". Arimidex is a VERY potent sulfatase inhibitor, which inhibits estrone. It is a moderately strong aromatase inhibitor but quite weak as compared to aromasin or letrozole). This is fine for women with breast cancer who produce percentage wise very high levels of estrone (the weak estrogen), which can be converted to estradiol (the strong estrogen) via aromatase.
For men this is generally not very good, especially for men on TRT or a test based AAS performance cycle since sulfatase inhibitors have very little effect on exogenous testosterone. Actually its generally not a good thing since it nearly completely eliminates estrone, while still allowing estradiol. If you have a choice as a man, you want estrone (weak estrogen) with near total elimination of estradiol (strong) Yes you still need some but in men this is the one that causes azll the negative side effects. Aromasin do inhibit sulfatase, though to a lesser extent than the competitive inhibitors (arimidex and letrozol). It is a potent aromatase inhibitors and highly suppress estradiol. Since exogenous test converts to estradiol via aromatase, Aromasin is much better suited. Letrozol is more like a total killer. It takes out everything and harsh. Nothing will supress your sex drive like it will. Also raise your bad lipids etc.. Aromasin will do the opposite.
beautifully clarified. thanks.
I would expect nothing less from you. Always thorough and straight to the nuts and bolts. I am still afraid of Letro so as dak979 said, I keep it around for emergencies. It has completely reversed gyno for me in the past when AI's failed. Something is quite different about Letro. It is POWERFUL! Good post. +3
That's the point I'm making Nitti. I know it's potent and most are scared of it. But it also has it's good points. The problem lies in that no one really knows how to dose it as an AI. Now is 2.5mg of Letro more potent that 1mg of Adex yes I agree it is. But mg for mg I think they are pretty close in effect. I think the mystic in letro is that it has been shown to reverse gyno where other AI have failed. Think about this, no one takes 2.5mg of adex a day or even E3D as an AI. No one does 1.25mg of adex EOD but that is the doses I've seen some people use letro. I think it has a place when used at a low dose even more so for those with high BF% (18% and up)are those prone to gyno. When I say low dose I mean dose such as .25mg to .5mg E3D. It's also another tool for those who can't take adex.
Anon.25mg-.5mg are considered on cycle E2 support doses. Very good write up man. Definitely needed to be covered here.
I can tell u from personal experience, that letro is way more potent than arimidex or aromasin. Regardless if it is really 98% or not, I will never use letro as an AI for a cycle. Ill keep it on hand for emergencies, that I doubt will ever occur with modest cycles.
just my .02
Thanks for replying. Can you share from you personal experience at what dose you used it and what was the out come. What compounds you were cycling and dosage when you used letro.
Test E 500mg/wk 12 weeks
Dbol 30 ramped up to 50mg/day over 4 weeks
The only reason I used Letro is because I got a couple of pills free from a friend. It's HG, bought straight from the pharmacy. That shit is VERY expensive btw.
I used 1/4 pill, which amounts to 0.625mg, twice per week, with my Test E shots. Made it easier to remember. So basically 1 pill of Letro lasts for 2 weeks.
Outcome: weak/cracking joints, libido gone, always felt down. Also felt gains were coming on a bit slow..
Anyways lesson learned. For that same cycle above, Aromasin at 12.5mg EOD does the trick
Good post and inof dak979. I can't take adex for the same reasons you posted. It just dries me out to much. I think it has a place for some people as I posted above.
very good information to have mega... excellent post
Thanks GRRRL