# Half lives of AI's



## coltmc4545 (Aug 8, 2012)

Ok so I'm writing this thread due to seeing a ton of people lately running Aromasin EOD. We need to think of half lives of AI's just like we think about the half lives of esters of gear. Some of this is copy and paste info as I'm too lazy to write everything out in my own words, and some of this is in my own words. So here we go....

*First let's define what an AI is and what they're used for.*

AI is short for Aromatase Inhibitor. Aromatase Inhibitors prevent the conversion of androgens into estrogen in fat, muscle, breast, and brain. Aromatase inhibitors work by inhibiting the action of the enzyme aromatase, which converts androgens into estrogens by a process called aromatization. As breast tissue is stimulated by estrogens, decreasing their production is a way of suppressing recurrence of the breast tumor tissue. Estrogen is produced and acts locally in these tissues, but any circulating estrogen, which exerts systemic estrogenic effects in men and women, is the result of estrogen escaping local metabolism and spreading to the circulatory system. 

*What are the different types of AI's?*

There are many different AI's out there. The most common used in the BB world are exemestane (Aromasin or "stane"), anastrozole (arimidex or "adex"), Letrozole (femera or "letro") Some people might argue that tamoxifine, or nolvadex, can be used as an AI. Nolva is NOT an AI. Nolva is a SERM. It has been used in plenty of studies and was the go to drug for years for gyno help in the BB world. It still is used by BB for reducing gyno but has actually been shown in recent studies to not affect steroid induced gyno as well as it has in gyno caused by puberty in males. Which brings me to another point, taking Nolva will not prevent high e. SERMs DO NOT lower estrogen. SERMs block estro from attaching to the breast tissue. They sit in the estrogen receptor and there is no room for the estrogen to attach to the receptor making it impossible for the cells to recieve estrogens signals to grow and multiply. After all, were not just trying to prevent gyno, were trying to control our estrogen levels which we do by taking AI's.

*Breakdown of types of AI's*

_Aromasin_- Exemestane is an irreversible, steroidal aromatase inactivator, structurally related to the natural substrate androstenedione. It acts as a false substrate for the aromatase enzyme, and is processed to an intermediate that binds irreversibly to the active site of the enzyme causing its inactivation, an effect also known as "suicide inhibition." In other words, Exemestane, by being structurally similar to the target of the enzymes, permanently binds to those enzymes, thereby preventing them from ever completing their task of converting androgens into estrogens. No need to taper dosage on stane as there is no risk of estro rebound. In laymans terms it kills estrogen.

_Arimidex_- Anastrozole binds reversibly to the aromatase enzyme through competitive inhibition, inhibits the conversion of androgens to estrogens in peripheral tissues (outside the CNS), and a few CNS sites in various regions within the brain. Adex needs to be tapered down as it can cause an estro rebound as it doesn't kill estro, it attaches itself to it.

_Letrozole_- Letro, just like arimidex, reversably binds to the aromatase enzyme. It also needs to be tapered. Letro is probably the most toxic and harshest of the 3. Be careful with letro as it will put you on your ass.

*What are the half lives of these AI's and how often should you take them?*

Here's where we get to the point of all this jiber jabber I have posted.

_Letrozole_ -Letro's half life is about 2 days. It reaches steady blood plasma levels in 2-6 weeks (study showed this at a daily dose of 2.5mg although I couldn't imagine taking this stuff at 2.5mg ed for 6 weeks) So basically you can dose letro eod although when I read the word "about" 2 days, personally I'd dose everyday. Like I said above, letro is no joke. If using for an AI, start at a VERY VERY low dose like .25 mg ed. This stuff will crash your E and have your joints feeling like they're made of concrete. It's also been shown to increase the risk of osteoperosis and has been shown to weaken bone structure. Also don't forget to taper letro so you don't get an estro rebound!!

_Arimidex_ - Adex's half life is shown to be 48.6 hours which means it is ok to dose adex EOD (every other day). A usual starting dose is .25-.5 mg EOD. Just like letro, taper down once coming off so you don't rebound.

_Aromasin_ - Stane's half life is 27 hours which means to achieve stable blood plasma levels, it needs to be dosed ED (everyday) A usual starting dose is 12.5mg ed. If I run it all the way through cycle instead of just starting when signs of high e are noticed, I start at 6.25mg ED. You do not need to taper with aromasin as like was shown above, it's a suicidal inhibitor and you won't get any estro rebound. Aromasin is the AI of choice for me for this reason.



I hope this info clarifys things for people. Like I said in the beginning, think of AI's, SERMs, hell even peptides and SARMs, the same way you think regarding esters in different compounds of gear. The goal is to achieve stable blood plasma levels. We do this by recognizing the half lives of these chemicals. The more stable our blood plasma levels, the greater the effect of whatever chemical we're using has AND the less chance we have for side effects from that chemical. 

-Colt


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## 69nites (Aug 8, 2012)

For a lot of us 12.5 mg a day is overkill. 

Same as test injection people are too concerned with stable levels. Your natural levels are NOT stable. 

There is a saying about the best laid plans of mice and men.


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## Jawey (Aug 8, 2012)

Thanks Colt, very informative. Kinda sucks I only have 12.5mg caps of Aromasin.. Guess you gotta work with what you got!


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## coltmc4545 (Aug 8, 2012)

69nites said:


> For a lot of us 12.5 mg a day is overkill.
> 
> Same as test injection people are too concerned with stable levels. Your natural levels are NOT stable.
> 
> There is a saying about the best laid plans of mice and men.



This is why I prefer stane in liquid form over pill. I can easily dose at 6.25 Ed and I don't crash my e.

I think people should be concerned with stable levels when putting things in our bodies that aren't naturally orcuring. Maybe not to the point of making threads with spreadsheets on em  lol It's the same reason we tell people not to frontload, or increase dosages of test from 500 to 750, because the spike will cause more sides. I'm not just speaking about bro science and what I saw so and so say on this or that board, I'm speaking from my own experience.


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## coltmc4545 (Aug 8, 2012)

Jawey said:


> Thanks Colt, very informative. Kinda sucks I only have 12.5mg caps of Aromasin.. Guess you gotta work with what you got!



You can cut open your caps, split the powder in equal piles, stir a pile into some oj or Gatorade. That takes you down to 6.25. There's a way around almost every obstical brotha!


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## TheLupinator (Aug 8, 2012)

Aromasin is the superior AI...


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## stb1041 (Aug 8, 2012)

How do so many people use Aromasin EOD successfully? There is a lot of debate about the need to use exemestane ED even though the half life is so short.  The drugs effects can last longer even after the drug is not active in the body.


Not trying to argue or say that u are incorrect, just wanting an answer to this


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## Shane1974 (Aug 8, 2012)

This AI business is a complicated matter to me.


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## Omegareign (Aug 8, 2012)

Everyone is different though.  I run my aromasin at 25mg ED, for one, cause Ive gotten gyno before and never want it again, for two, we all know these research companies can be unreliable with dosages so a little extra won't kill you.  Find your sweet spot.


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## Curiosity (Aug 8, 2012)

coltmc4545 said:


> This is why I prefer stane in liquid form over pill. I can easily dose at 6.25 Ed and I don't crash my e.
> 
> I think people should be concerned with stable levels when putting things in our bodies that aren't naturally orcuring. *Maybe not to the point of making threads with spreadsheets on em*  lol It's the same reason we tell people not to frontload, or increase dosages of test from 500 to 750, because the spike will cause more sides. I'm not just speaking about bro science and what I saw so and so say on this or that board, I'm speaking from my own experience.



Heyyyyy..... ha ha.

I've been taking Aromasin @ 12.5 EOD and honestly its working fine, I would prefer to dose it at 6.25 ED but I have 12.5 mg caps. I could split it up like you suggested though. On the other hand, however, as a suicidal inhibitor you could possibly expect a dose of it to keep your aromatase levels low for a period of time after the compound itself is out of your system. I'm not sure how long it takes for the body to produce more aromatase to replace what was de-activated by the aromasin. Anyone have any knowledge of that?

Anyway, thanks for the post, maybe I'll start splitting up my caps and see how it goes.


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## 69nites (Aug 8, 2012)

coltmc4545 said:


> This is why I prefer stane in liquid form over pill. I can easily dose at 6.25 Ed and I don't crash my e.
> 
> I think people should be concerned with stable levels when putting things in our bodies that aren't naturally orcuring. Maybe not to the point of making threads with spreadsheets on em  lol It's the same reason we tell people not to frontload, or increase dosages of test from 500 to 750, because the spike will cause more sides. I'm not just speaking about bro science and what I saw so and so say on this or that board, I'm speaking from my own experience.


AI are to prevent estrogen buildup. Unless your levels are getting jacked up high every single day its not necessary to dose it every day.

Your concern is not the amount of aromasin in your system, its the amount of estrogen. If the goal is to reduce your day to day estrogen levels aromasin eod works just as well as ed. No one gets a roller coaster of sides from aromasin unless they are lowering their estrogen levels too much.

My blooodwork always shows in range estrogen at 12.5 mg eod. For me THAT is all that matters.


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## 63Vette (Aug 8, 2012)

69nites said:


> For a lot of us 12.5 mg a day is overkill.
> 
> Same as test injection people are too concerned with stable levels. Your natural levels are NOT stable.
> 
> There is a saying about the best laid plans of mice and men.



I agree with this ^^^^ and I agree with Colt. 
Because it is such a highly effective suicide inhibitor, exemestane does NOT need (IMHO) to take it every day unless you want your estrogen to be too low. I have learned that for me, I am better off with 12.5 mg eod or even 25mg every third day. 

I do agree that with a typical AI a more frequent dose can be beneficial since they compete for the same binding enzymes and receptors as the test that would be converted to estrogen do. 

As for Letro I would never advise taking it unless you have obvious symptoms of gyno and then it is effective  treatment when tapered up-stabilized-and tapered down. Keep in mind that everyone's body is a little different and we may differ on what works best for us.

Good information and a great post Colt.


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## stb1041 (Aug 8, 2012)

This was a post made by Chip Wadowski on this topic: 

Exemestane, sold under the name Aromasin® by Pfizer, is an orally available suicidal aromatase inhibitor. <This sentence describes exactly why exemestane is the king of anti-e's for bodybuilding purposes.

Because exemestane is steroidal this gives it a favorable estrogen suppression profile and confers a few really awesome benefits over other anti-estrogens both on paper and in real experience. Steroidal anti-estrogens have the benefit of being lipid-friendly and they all lower sex hormone binding globulin which increases the ratio of free to bound testosterone, which as many experienced BB'ers know can have a relatively profound positive impact on gains.

I think it is important to understand how drugs work in order to properly dose them, exemestane is a suicidal aromatase inhibitor, this means that it binds with aromatase enzymes and as it does so permanently disables the enzyme and destroys it. Hence the "suicidal" this chemical is like a kamikaze pilot out to destroy your aromatase enzymes which is what makes it so special.

Exemestane's half life in the male body is actually very short (~9 hours) and it is quickly eliminated, however, since as soon as it enters your bloodstream it quickly destroys 80-90% of the aromatase enzymes present in your body, it is effective in maintaining significant reductions in estrogen for up to 72 hours after a single 25mg dose. Estrogen levels only begin to rise again after your body has begun to make new aromatase enzymes to replace the ones destro by exemestane.

There is a great study on the pharmacokinetics of exemestane in men which found the following:
-24 hours after one 25mg dose estrogen levels are reduced by 70-80%
-72 hours later estrogen levels are still 40% below baseline even though the drug itself is almost completely eliminated
-120 hours after initial dose estrogen levels return to baseline (without rebounding)

this means that you can find the timing and dosage that works for you, i've seen some guys recommend between 25mg ed and 12.5mg e4d, and you can see why both are effective while providing different levels of estrogen suppression, and it is this flexibility that makes exemestane such a versatile anti-e.


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## coltmc4545 (Aug 8, 2012)

I'm not talking a rollercoaster of sides from aromasin. I'm talking about your estro rollercoastering. You can't tell me that estro levels don't fluctuate on a day to day basis. Go get bloodwork done on cycle one day then go back the next day and get another draw. The numbers will differ. I'm not saying they'll be a huge difference, but there will be one. Let me ask you this, when running test e do you inject once a week or twice a week? After all the half life of e is 7 days correct? 10 with test c. So why inject twice a week with long esters if the relativity of half lives and blood stability levels don't have anything to do with side effects? Why do we inject long esters twice a week? Some even go as far as M/W/F. Hell I've seen a vet on ology talk about how he injects long esters ED. We do this to create more stabile blood plasma levels which in turn produces less peaks and valleys which means what? Less side effects. I'm not saying your point is wrong, it works for you and that's what matters to you. This is what works for me. I just don't see why people talk about stabile blood levels and half lives of gear but then dose something with a little over a full days half life eod. That would be like pinning test e once every 2 weeks. After all if stanes half life is about 24 hours and you take it every 48 hours that would be the same as pinning test e that has a half life of 7 days every 14 days. My point of this write up isn't to say your wrong and do it this way, it's more to start getting people to think about half lives in everything they use, not just what oral or oil they're using.


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## 69nites (Aug 8, 2012)

coltmc4545 said:


> I'm not talking a rollercoaster of sides from aromasin. I'm talking about your estro rollercoastering. You can't tell me that estro levels don't fluctuate on a day to day basis. Go get bloodwork done on cycle one day then go back the next day and get another draw. The numbers will differ. I'm not saying they'll be a huge difference, but there will be one. Let me ask you this, when running test e do you inject once a week or twice a week? After all the half life of e is 7 days correct? 10 with test c. So why inject twice a week with long esters if the relativity of half lives and blood stability levels don't have anything to do with side effects? Why do we inject long esters twice a week? Some even go as far as M/W/F. Hell I've seen a vet on ology talk about how he injects long esters ED. We do this to create more stabile blood plasma levels which in turn produces less peaks and valleys which means what? Less side effects. I'm not saying your point is wrong, it works for you and that's what matters to you. This is what works for me. I just don't see why people talk about stabile blood levels and half lives of gear but then dose something with a little over a full days half life eod. That would be like pinning test e once every 2 weeks. After all if stanes half life is about 24 hours and you take it every 48 hours that would be the same as pinning test e that has a half life of 7 days every 14 days. My point of this write up isn't to say your wrong and do it this way, it's more to start getting people to think about half lives in everything they use, not just what oral or oil they're using.



I have injected test e once a week and saw no noticeable difference from 2x.

I take my dbol in one large dose preworkout. I take tne on workout days only.

Your levels are supposed to fluctuate. People are getting all knitpicky about their stable levels. Your body does not produce stable levels. It produces hormone spikes. 

Stable levels IME do not produce as good of results as hormone spikes.

If my estrogen is in range on every blood test I take I don't give a shit about the variance.


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## Curiosity (Aug 8, 2012)

Very interesting thread guys, good discussion! 

I have been wondering about this for a while since I've been taking my aromasin EOD for the last few weeks due to the dosing of the caps I have, and after reading this whole thread I have to conclude that EOD dosing is not going to cause significant estro fluctuations or problems.


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## 0tj0 (Aug 8, 2012)

coltmc4545 said:


> This is why I prefer stane in liquid form over pill. I can easily dose at 6.25 Ed and I don't crash my e.
> 
> I think people should be concerned with stable levels when putting things in our bodies that aren't naturally orcuring. Maybe not to the point of making threads with spreadsheets on em  lol It's the same reason we tell people not to frontload, or increase dosages of test from 500 to 750, because the spike will cause more sides. I'm not just speaking about bro science and what I saw so and so say on this or that board, I'm speaking from my own experience.



Not sure if Im offended? or flattered?

Just kidding. Great post colt!


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## coltmc4545 (Aug 8, 2012)

To each his own.

 Not sure why you keep referencing your body doesn't produce stabile levels 69. Your body doesn't produce dbol or tne or test levels over 1500 either. When your body's natural hormone levels fluctuate it also fights to bring itself back to homeostasis also correct? When your shut down then that's not happening so we do it ourselves with AI's and test. Like I said, this is more so people get an understanding of half lives, and that everything were putting in our bodies has them. Plus it seems alot of research companies put out tablets and not liquid. Liquids of course easier to split dosing up into smaller doses. So people with tabs or caps, not wanting to crash thier e, dose eod.


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## 69nites (Aug 8, 2012)

coltmc4545 said:


> To each his own.
> 
> Not sure why you keep referencing your body doesn't produce stabile levels 69. Your body doesn't produce dbol or tne or test levels over 1500 either. When your body's natural hormone levels fluctuate it also fights to bring itself back to homeostasis also correct? When your shut down then that's not happening so we do it ourselves with AI's and test. Like I said, this is more so people get an understanding of half lives, and that everything were putting in our bodies has them. Plus it seems alot of research companies put out tablets and not liquid. Liquids of course easier to split dosing up into smaller doses. So people with tabs or caps, not wanting to crash thier e, dose eod.


I keep referencing because people talk about stable levels like its unhealthy to have unstable levels. 

I dislike regurgitation of BS info.  If eod dosing keeps your estrogen levels in normal range at all times why do you care about making something simple complicated? 

I think these kinds of graphs are cool for looking at a test blend or determining how long your kick start should be but that's about it.

Looking at things like this is what they do before clinical trials. Then they determine based on the real life use what is the best way to administer. Why take a step back when you already know what works?


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## coltmc4545 (Aug 8, 2012)

People are talking about stable levels because maybe possibly they get side effects from blood levels fluctuating up and down. Maybe you don't and you're lucky. Good for you. Me on the other hand, I have horrible bacne which I've been able to manage pretty well this cycle from pinning Ed aka keeping my blood levels stable. If you disagree, that's fine. Like I said to each his own. What works for you might not work for me. How is my post regurgitating bs info? Everything I posted is backed up by actual science, not bro science on a board.

Show me a clinical trial of use of AI's that they dosed aromasin eod though. Everyone that I read while writing the initial post talked about dosing 25mg ED. You can't say they do this before clinical trials and then find out what works because I have yet to read an actual clinical trial on aromasin where it wasn't administered ED. I've read nothing but posts on boards from bro's aka bro science about dosing eod. If its a step backwards to say to dose Ed then it's also a step backwards giving people advice on pinning LE's twice a week also. I don't see how anything I posted was regurgitating bs info when all the info I posted is backed up by actual clinical studies. Not by a dude on a steroid board saying it works for him. I'll take science over broscience any day.


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## Get Some (Aug 8, 2012)

I'M GOING TO RESPECTUFULLY DISAGREE WITH THE STATEMENT THAT AROMASIN NEEDS TO BE DOSED EVERY DAY

This is just simply false and bad information. The half life of the drug is OVER 24 hrs or one day. Just because the "half-life" of something is "about" one day doesn't mean you need to reintroduce it to your body on a daily basis. EOD will work just fine and has for many people for many years. "Stable Blood Plasma Levels" are much less important than they are made out to be. I guess I just hate the fact that so many people act like blood levels are are a see saw of sorts and they constantly have to keep it balanced. It's much less complicated than it would appear on the surface.

Arimidex... the half life is closer to 3 days than 2. 48.6 Hrs is what's listed on Wikipedia... rule of thumb, NEVER trust wikipedia 100%. HOWEVER, the half life of arimidex is much less important than Letro or aromasin. The reason that adex usage works so well on an ED basis at lower dosages is because of the violent nature of it's mechanism of action. Keep in mind this drug was created to be a "warrior" in the fight on breast cancer because tamoxifen was not good enough. This is info taken directly from the Astra-Zeneca website concerning arimidex:



> Absorption of anastrozole is rapid and maximum plasma concentrations typically occur within 2 hours of dosing under fasted conditions.



It goes on to state that when taken with food the peak concentration occurs 5 hours after administration (which is still very quick considering the half life). Arimidex is very good for combatting gyno because of the "attack mode" that it gets into right away. Levels stabilize after about 7 days of daily administration. All that being said, if you don't experience too many gyno symptoms (you are lucky) then dosing it E3D will work just fine.

Aromasin is superior because it's the most effective with the best delivery method. Here is a quote from the Pharmacodynamics section of the Pfizer website about Aromasin:



> After a single dose of exemestane 25 mg, the maximal suppression of circulating estrogens occurred 2 to 3 days after dosing and persisted for 4 to 5 days.



So, as you can see, Aromasin continues to work long after the "half-life" has passed.

COLT, I understand you are just relaying information, but the "clinical studies" you speak of were done with the intent to prevent and reverse the effects of breast cancer....not nearly the same as preventing aromatization in healthy males with elevated testosterone. One is benign and the other is malignant so time is of the essence, thus the ED use.


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## coltmc4545 (Aug 8, 2012)

I stand corrected then. Thank you get some for posting actual scientific information. I'm much more apt to be open minded to science then bro science. You are correct, the studies I got the information from were studies done on post menopausal women but were also done on men with breast cancer and gyno. I actually didn't pull the info on wikipedia lol I trust nothing on that site. Anyways like I said, I stand corrected. Although for me, I'll probably continue dosing aromasin ED as that's what as worked for me throughout the years.


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## Moppy1 (Aug 9, 2012)

Why does everyone say that Letro is more toxic or worrisome?  I have been taking 1.25 mg EOD for years and have not noticed any negatives, and my blood work always shows my E levels to be low enough.  What sort of negatives have people noticed from Letro?  Should I switch to aromasin?  Any advice?


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## Get Some (Aug 13, 2012)

Thanks for taking that in stride man, I just want to make sure that everyone is aware of the situation at hand. Also, if something works for you AND your levels come back stable, then keep on truckin man! The individual experience form drug to drug varies so much that blanket statements about dosing and length of cycle really are inaccurate.... but it's the best we have 

You have to be careful with science when concerning the needs of our brotherhood here. There are very few studies done on what we use the drugs for. So, we have to create our own set of rules and help each other out to make sure everyone achieves success.



coltmc4545 said:


> I stand corrected then. Thank you get some for posting actual scientific information. I'm much more apt to be open minded to science then bro science. You are correct, the studies I got the information from were studies done on post menopausal women but were also done on men with breast cancer and gyno. I actually didn't pull the info on wikipedia lol I trust nothing on that site. Anyways like I said, I stand corrected. Although for me, I'll probably continue dosing aromasin ED as that's what as worked for me throughout the years.


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## Get Some (Aug 13, 2012)

Far too often people associate things that work really well with, "oh, that stuff works awesome so it must be less safe." To be honest, I beleive that everyone should try all 3 of the common AIs in different cycles and see which works best for them. For me, letro is best suited for when I already have gyno and need to kill it quick. I have come to love aromasin for maintenance during cycles. If you really have a problem with hairloss, then go with arimidex because it will be a little easier on the hairline than aromasin. 



Moppy1 said:


> Why does everyone say that Letro is more toxic or worrisome?  I have been taking 1.25 mg EOD for years and have not noticed any negatives, and my blood work always shows my E levels to be low enough.  What sort of negatives have people noticed from Letro?  Should I switch to aromasin?  Any advice?


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## BBE (Aug 15, 2012)

The half life of aromasin in men is significantly less than the 27 hours that's always reported.  Those studies are done on women who are using it for medical reasons such as breast cancer treatment.  Zeek had a very good post and article about it over on ology about a year ago.  Basically the elevated androgen levels in men bring the half life of aromasin down closer to around 12 hours.

2x a day dose on aromasin has always been far superior for me.

But as far as lipid values, shbg lowering, and all of that good stuff, it is for sure the superior AI


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## Get Some (Aug 15, 2012)

I respect your opinion and experience and have found an article below that speaks of what you are talking about. However, dosing twice a day is just not necessary. I can see if it's necessary for your psyche then that's fine. 

http://www.ncbi.nlm.nih.gov/pubmed/14671195

Here is a quote from the article:



> The PK properties of the 25-mg dose showed the highest exemestane concentrations 1 h after administration, indicating rapid absorption. The terminal half-life was 8.9 h. Maximal estradiol suppression of 62 +/- 14% was observed at 12 h.



So, as you can see, they observed the"half-life" to be around 8.9 hours with peak suppression around 12 hours. This brings up the point that I always try to emphasize... lag time. There is always a lag time between "peak concentration" and "peak performance." Compounds being instantaneously utilized is only viable in a lab setting with no outside variable or other mechanisms of action. A single process without a single variable is required. So, with the maximum results ocurring around 12 hours, you can safely assume that it starts to drop off after that. HOWEVER, what you are failing to take into account is the stress that "maximum efficieny" puts on your body. If all compounds worked at maximum efficiency of peak level for long periods of time then we would be stuck with likely unbearable side effects for most of the duration of use. You will only see such cases in drugs that are used to aggressively treat debilitating illnesses that such harsh side effects are acceptable considering the circumstances. So, what I'm getting at is that you DO NOT WANT (insert meme here) the drug to be at maximum levels for long periods of time. Just because the levels are on the decline doesn't mean that it's not continuing to work. In fact, it will continue to do it's job for several days after the first dose.



> To characterize its suppression of estrogen and its pharmacokinetic (PK) properties in males, healthy eugonadal subjects (14-26 yr of age) were recruited. In a cross-over study, 12 were randomly assigned to 25 and 50 mg exemestane daily, orally, for 10 d with a 14-d washout period



Two things here....

1. The study only consisted of 12 males of young age. It does not state how many were over 20 and how many were under the age of 20. Personally I feel like they need more people to be involved in a study like this and analyze the control group more. Also, the drug's interactions WERE NOT measured against increased/rising levels of androgens and estrogens that would be present in an AAS cycle. You'll find that in presence of an added workload, it can take much longer for an enzyme to complete it's job and attach to a ligand. Even if the reception time stays similar, there is the issue of using a similar dose to combat a far larger army. If you take the example of the issue of breast cancer in women (who naturally have higher estrogen levels than males by far) it shows that the Aromasin has a half life around 27 hours and will continue to be effective for longer than 5 days in most cases. This is why I believe that in the presence of estradiol levels that exceed the standard for males, the drug will present itself over a longer half life in order to perform it's job correctly.

2. The quote mentions a 10 day study with a 14 day "washout" period. This essentially tells me that the system will be rid of the drug (or low enough levels to consider it gone) after about 4 days. This would in essence suggest that it has undergone almost 11 half life cycles of 8.9 hours. Using simple math we can cut that number to 5.5 half life cycles from the end of day2 to the end of day 4. see below:

Working backwards, 5.5 x 2 = 11 times higher concentration in day 2 as opposed  to day 4. 11 times higher is certainly significant in considering when to dose again. You could also say that considering that 8.9 half life we could assume that the levels would be 11 times higher at peak than at the end of day 2. You might also think that is significant, but again, declining levels are necessary to let the inhibitor do it's job and bind to the ligand and block the estradiol. Increasing levels at the time of "fulfillment" could actually be more harmful than levels that are too low. 

I hope that makes sense for most of you, but if not feel free to PM me and I think I can provide you with some visual aid to make it clearer....no, I'm not referring to my pp when I say "visual aid" 



BBE said:


> The half life of aromasin in men is significantly less than the 27 hours that's always reported.  Those studies are done on women who are using it for medical reasons such as breast cancer treatment.  Zeek had a very good post and article about it over on ology about a year ago.  Basically the elevated androgen levels in men bring the half life of aromasin down closer to around 12 hours.
> 
> 2x a day dose on aromasin has always been far superior for me.
> 
> But as far as lipid values, shbg lowering, and all of that good stuff, it is for sure the superior AI


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## Get Some (Aug 15, 2012)

ok fine, here's a chart, lol....

The chart below shows 3 different types of aromasin administration... coated tablet with no food, suspension with no food, and coated tablet after food. The typed of administration are not important to us in this moment, but as you can see, average plasma concentrations of estrogen continue to decrease well past 48hrs. So, if the drug continues to work that long after administration AND can be absorbed in less than an hour and reach maximum efficiency in less than 12, why do we need to dose it multiple times or even once daily? Oh wait.... because we don't


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## Curiosity (Aug 16, 2012)

Get Some, thanks for all the great information man. I have to say you make a very compelling case that it is totally fine to dose aromasin EOD. I'm convinced until someone else comes up with a stronger counterargument.


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## Get Some (Aug 16, 2012)

Trust me man, I feel so strongly about it that I wouldn't even say it's "fine" but more like "preferred"... I've been researching this stuff for years now and that's why I get a bit technical when it comes to these things because most people couldn't google in a year what I could pull from the back of my brain in a few minutes, lol. 

Just wanted to reiterate again that  Adex is a fine AI as well and has worked for me. I encourage everyone to try each one out in different cycles to see what they think. 



Curiosity said:


> Get Some, thanks for all the great information man. I have to say you make a very compelling case that it is totally fine to dose aromasin EOD. I'm convinced until someone else comes up with a stronger counterargument.


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## SHRUGS (Aug 17, 2012)

Get Some, bro, You my friend are a great help around here and your knowledge is greatly appreciated. Thank you for educating me and others. Much appreciated. Thank u!


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## BBE (Aug 27, 2012)

can't argue with the research there bro.  That was some great stuff, I appreciate the read.  I don't know how else to validate it other than for me personally it really does make a difference for me splitting the dose.  I've used aromasin as my only AI for years now for both cycling and trt, and I things work out much better for me using the same dose, but splitting it in 2 doses per 24 hour period.  So if I was gonna do a basic 12.5mg dose ED, I'd do 6.25mg 2x ED.

But like I said, I can't argue with all of that research which was AWESOME to read!  Keep that info coming bro, I learn new stuff all the time reading your posts


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