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Guide Aromatase Inhibitors 101 – Complete Guide for Height Growth, Puberty Delay & Estrogen control

milchbubi88

i just want to love and be loved
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(this is a repost from my org account)
When it comes to heightmaxxing people always recommend the combination of HGH and an AI
but what even are Aromatase Inhibitors?

This guide will teach you everything you need to know about Aromatase inhibitors!
read this guide if you want to gain knowledge about HGH → https://looksmax.org/threads/hgh-101-everything-you-need-to-know.1423722/

THE ROLE OF ESTROGEN WHEN IT COMES TO HEIGHT
Human linear growth occurs at the epiphyseal (growth) plates of long bones, which are zones of cartilage undergoing endochondral ossification.
These plates consist of:
Resting zone: reserves of chondrocytes
Proliferative zone: active cell division
Hypertrophic zone: cell enlargement and mineralization

Bild 2025 08 09 115620286 Photoroom


So, bone lengthening continues until the growth plate closes, which marks the end of height increase.
This closure process is triggered by estrogen

How?
Estrogen closes growth plates by binding to estrogen receptor alpha on chondrocytes, pushing them to mature faster while depleting the reserve of stem-like cells that keep the plate active once these cells mature too quickly, the growth plate runs out of new cells that can make more bone length.

Estrogen also makes the plate release signals that pull in blood vessels, which bring bone building cells
These cells replace the last bits of cartilage with solid bone.
When that happens, the growth plate turns into a thin bony line, and you can’t get any taller.


So make sure your plates are open before you take action
you can confirm this through an x-ray of your hand or knee

1754838598781

The younger your bone age, the more potential you have to grow
ideally it should be younger than 16, but even after that you could grow a few more cm


but once plates are closed, Limb lenghtening is the only way to increase height other than fixing posture and wearing shoe-lifts

WHAT ARE AROMATASE INHIBITORS?

The story starts back in the 1950s and 60s when scientists first figured out how estrogen is made in the body.
They realized that if you could block the aromatase enzyme, you could lower estrogen levels and potentially slow down some type of cancers

In the 1970s, the first aromatase inhibitors were developed. These early drugs, like aminoglutethimide, weren’t very selective and had a lot of side effects.
They worked by binding tightly to the enzyme and basically breaking it, but because they weren’t very specific, patients often had issues.

Then, during the 1980s and early 90s, researchers worked on making better inhibitors.
Nonsteroidal ones came along, such as fadrozole and vorozole, which were safer and more targeted.

The big breakthrough happened in the 1990s: anastrozole, letrozole, and exemestane were invented
These drugs were more effective, had fewer side effects, and became the new standard treatment for hormone-sensitive breast cancer
They’re still widely used today because they work well and patients tolerate them better than older drugs.

Aromatase inhibitors also come to play for treating male hypogonadism or delaying puberty
(and with that being able to grow for a longer period of time)

Aromatase inhibitors are compounds that block or kill the enzyme aromatase, which converts testosterone into estrogen
Aromatase is a cytochrome P450 enzyme, encoded bythe CYP19A1 gene.
It catalyzes the aromatization of the A-ring ofandrogens, specifically:
Testosterone into Estradiol and Androstenedione intoEstrone


(Estrogen refers to a group of hormones that include estradiol, estrone, and estriol, with estradiol being the most potent and prevalent)
By lowering estrogen levels, AIs can delay epiphyseal fusion, extending the window for longitudinal bone growth

The Aromatization Reaction (Biochemistry)

4177656_1717615866064.png

At the molecular level, aromatase performs a three-stepoxidation of the androgen substrate’s A-ring:
Hydroxylation of the 19-methyl group (C19).
Conversion to a formyl group.
Aromatization of the A-ring, forming an aromaticphenol (the hallmark of estrogen).

This process is NADPH-dependent, and localiezd in the endoplasmic reticulum of cells
By taking an aromatase inhibitor we can block this process leading to less estrogen

ANASTROZOLE, LETROZOLE AND EXEMESTANE IN COMPARISON
The main difference is that anastrozole and letrozole are non-steroidal aromatase inhibitors, while exemestane is a steroidal aromatase inhibitor.
Simply put, this means that anastrozole and letrozole anesthetize the aromatase enzyme while exemestane kills the aromatase enzyme
(The enzyme is reproduced by the body)

GENERAL COMPARISON
Property
Anastrozole (Arimidex)
Letrozole (Femara)
Exemestane (Aromasin)
Type
Non-steroidal, reversible
Non-steroidal, reversible
Steroidal, irreversible
Estrogen Suppression
~50–70% (dose dependent)
~80–98% (very potent)
~65–85% (irreversible)
Half-Life
~48 hrs
~40–60 hrs
~24–27 hrs
Rebound Risk
Medium if stopped fast
High (sharp increase)
Low (enzyme destroyed)
Titration Precision
High (easy microdose)
Moderate to difficult
Low (fixed dose tabs)
Bone Impact
Mild (long-term)
moderate to severe
moderate
Lipid impact
Mild, but could affect HDL
Moderate to severe
moderate
Onset of Suppression
~24 hours
Within hours
~24 hours (stronger than Anastrozole)
Peak Suppression
~2–4 days
~2–3 days
~2–3 days

PRICES
Source
Anastrozole Price (1mg)
Letrozole Price (2.5mg)
Exemestane Price (25mg)
Pharma (Brand)
$5–$10
$8–$15
$10–$20
Generic (Indian)
$0.50–$1.50
$1–$3
$1–$4
UGL (Chinese)
$0.20–$0.50
$0.30–$1
$0.30–$1

SIDE EFFECTS
Side Effect
Anastrozole (Arimidex)
Letrozole (Femera)
Exemestane (Aromasin)
Hot flashes
Common
Common
Common
Joint pain
Moderate
Moderate to severe
Mild to moderate
Fatigue
Mild to moderate
Moderate
Mild to moderate
Bone density loss
Mild (long-term use)
More severe if misused
Moderate (monitor needed)
Nausea
Mild
Mild to moderate
Mild
Mood changes
Possible
Possible
Possible
Headache
Occasionally
Occasionally
Occasionally
Increased cholesterol
Mild
Moderate to severe
Moderate
Muscle pain
Mild
Moderate
Mild
Exemestane is harsher on hair because of its androgenic metabolite, 17-β-hydroxyexemestane.
I’d recommend adding something like ru58841 if you choose exemestane.
(That said, hair loss from exemestane only happens if you’re genetically prone to it)


Side effects like losing cognitive abilities only occur when your estrogen is under 10 pg/mL for a longer period of time
this and hair loss were the side effects I was afraid of the most, but as long as you know what youre doing, you don't have to worry about them

Here is a study that proves Ais are safe when it comes to influencing cognitive abilities (if you dont crash E2 ofc)
STUDY https://pubmed.ncbi.nlm.nih.gov/20421333

Also, Ais can increase levels of endogenous Testosterone production in men by 30-60% which is a lot

The biggest downside of non-steroidal Ai's is the possible estrogen rebound

Estrogen rebound is a phenomenon that occurs when the body experiences an increase in estrogen levels after discontinuing or reducing the dosage of aromatase inhibitors like Anastrozole or Letrozole.

This rebound effect happens because these AIs suppress the production of estrogen, but once the AI is stopped, estrogen levels rise temporarily as the body's natural production resumes.

This abrupt rise in the body’s natural production of estrogen could lead to premature closure of growth plates, potentially impacting final height.

Missing a few doses of a non-steroidal Aromatase Inhibitors could cause that, so be careful when using one
rebound can be strongly reduced by tapering off slowly instead of stopping suddenly
but in comparison to exemestane, letrozole and Anastrozole are cheaper and better studied

My personal choice is Exemestane, because it has the least side effects and estrogen rebound isn't a thing
(but like I said, every AI works, just keep E2 at 15-20 pg/mL
and if youre using a non-steroidal one, be careful that you dont forget to take them)


DOSAGE PROTOCOLS AND BLOODWORK

Test your E2 to find the dosage you probably need
1 week into your Ai you should do another blood test to see if you should adjust the dose

You want to Target blood estradiol levels of 15–20 pg/mL and never go under 10 pg/mL
(for reference, normal estradiol levels for teenagers are around 20-50 pg/mL)

If you can't do blood tests, youre basically playing russian roulette, so be careful
in that scenario start a low dose, for example 6,25mg of Exemestane and adjust the dose slowly on how you feel and symptoms you experience

symptoms of low estrogen
Sudden joint pain/dryness

Drop in libido or morning erections
Brain fog, mood drop, irritability
Dry skin or hair shedding increase
Unexplained fatigue
if these occure, lower the dose

symptoms of high estrogen

Puffy face/water retention

Fat gain on hips/chest
Gynecomastia or nipple sensitivity
Emotional volatility or crying easily
Chronic bloating
if these occure you should up the dose

Also, here is an overview, how much different dosages suppress your estrogen

Anastrozole:
0.5 mg → ~50–60% E2 suppression
1 mg → ~80–85% E2 suppression
5 mg → ~85–90% E2 suppression (plateau)
Letrozole:

0.25 mg → ~60–65% E2 suppression
0.5 mg → ~75–80% E2 suppression
1 mg → ~85–90% E2 suppression
2.5 mg → ~90–95% E2 suppression
Exemestane:

6.25 mg → ~30–35% E2 suppression
12.5 mg → ~55–60% E2 suppression
25 mg → ~85–95% E2 suppression
Avoid over suppression (estrogen crash) and Monitor symptoms and do bloodwork.

BlOODWORK

(budget friendly)
Test Estradiol (E2)
Why: Directly shows if your estrogen is in your target range (~15–20 pg/ml).
When:
before the start to calculate the dose you need and then check again 1 week after the start

If everything is correct check 1 month later to see if its stable
then every 8-10 weeks
Total Testosterone + Free Testosterone

Why: AI can raise testosterone; high T can cause secondary effects (acne, aggression, libido swings).
When: Same time as E2 checks.

SHBG (Sex Hormone Binding Globulin)

Why: AI-induced changes in T and E2 affect SHBG, which changes free T availability.
When: every 8-12 weeks Alongside T/E2 checks.

Lipid Panel (Total Cholesterol, LDL, HDL, Triglycerides)

Why: Low E2 can lower HDL and raise LDL → cardiovascular risk.
When: Every 3 months.

Liver Enzymes (ALT, AST)

Why: Ais is metabolized in the liver; rare but possible liver stress.
When: Every 3 months or if symptoms appear.
(important if you drink alcohol)

Bone Health (long-term)

Why: Chronically low E2 can reduce bone density.
When: DEXA scan after 12+ months if running AI long-term.
(optional, but would be good)


simply put together

the baseline test would be:
E2 (sensitive), Total T, Free T, SHBG, Lipid Panel, ALT/AST

around 1 week after AI start:
E2 (sensitive) (optional Total T)

then E2 (sensitive), Total T, Free T, SHBG
every 8-10 weeks and lipids + liver enzymes every 3 months

You can do blood tests in private labs

IMPORTANT NOTES AND TIPS
The time when you take your Ai is not important (should still be around the same time)
But taking your Ai with a meal is
(alternatively, you can take your ai with a tablespoon of olive oil)

Storage:

Dry location with an ideal temperature of 15–25°C and no sun exposure
(just put it in your drawer)

Hormones return to baseline within 2–4 weeks after you stop taking your ai

weird, but don't eat Grapefruits and don't drink Grapefruit Juice

Grapefruit and its juice contain compounds that block the liver enzyme CYP3A4, which helps break down many drugs, including aromatase inhibitors.
This blockage can cause the ai to build up in your blood, and with that increase the risk of side effects

CLINICAL STUDIES OF HEIGHT INCREASE WITH AIS

1754759563737

STUDY https://ijpeonline.biomedcentral.com/articles/10.1186/1687-9856-2015-4

Aromatase inhibitors Alone
Boys with idiopathic short stature or delayed puberty treated with anastrozole (AI) showed around5cm increase in predicted adult height by delaying growth plate closure
STUDY https://pubmed.ncbi.nlm.nih.gov/16189252


Growth Hormone (HGH) Alone:
This study looked at kids with idiopathic short stature (ISS), meaning normal GH levels but short height.
HGH treatment increased adult height by an average of 4–6 cm compared to untreated children.
STUDY https://umraniyepediatri.com/storage/upload/pdfs/1732279204-en.pdf


Combination Therapy (AI + HGH):
combining growth hormone with aromatase inhibitors in adolescent boys with idiopathic short stature led to an average adult height increase of about 6 to 9 cm.
STUDY https://academic.oup.com/jcem/article/110/9/e2871/8125692?login=false


HOPEFUL

Boys grow 2.13 cm in average after the age of 18 without anything
a study shows, that on average, boys grew an additional 2.13 cm between ages 18 and 27, with some increasing by as much as 7 cm
absolutely hopeful study
STUDY https://pubmed.ncbi.nlm.nih.gov/6638938


AIS IN CONTEXT OF BODYBUILDING
1754824211762

i dont want this topic to be left out completely, but i will just cover the most important things

because of higher testosterone levels, the body converts more testosterone to estrogen
Ais can help to control estrogen levels during steroid cycles,
preventing side effects like water retention, bloating, and gynecomastia.

They’re used to maintain a healthy testosterone-to-estrogen balance, which supports better muscle gains, mood, and overall performance.
Additionally, by limiting estrogen, AIs can reduce fat storage and help bodybuilders achieve a leaner, more defined physique.

When Ais come to play in bodybuilding

if your Estradiol is too high and you experience side effects like
-Gyno

-Water retention
-Severe acne
-Mood swings (irritability or depression)

At High Doses or for Estrogen-Sensitive Users
some users don't need one even with +500 mg test a week
while some require an AI even with just 250 mg/week
(At ~500 mg testosterone a week most need an AI)

During Contest Prep
Ais reduce water retention, many bodybuilders use that to achieve a more defined and dryer look

Post-Cycle therapy (PCT)
After a steroid cycle to restore natural testosterone production
Often combined with SERMs (Clomid, Nolvadex)

SPECIAL TOPICS

AI Resistance
true resistance to aromatase inhibitors in men is very rare, but possible
In bodybuilding “resistance” usually means underdosing,
poor absorption of the product, or genetic differences in aromatase activity


In practice:
If estrogen stays high despite seemingly adequate AI dosing,
first rule out fake/underdosed product and high androgen load before assuming true resistance

Many UGL AIs are underdosed

Buy from tested sources (Janoshik reports).
and see how much impact they have on your E2 via bloodwork

Myths about estrogen

Myth 1: “Lower estrogen = more muscle gains.”
Truth: Too little estrogen impairs strength, recovery, joint health, and IGF-1 signaling, all critical for muscle growth.

Myth 2: “Estrogen is bad for men and should be eliminated completely.
Truth: Estrogen plays important roles in men, including bone haelth, brain function, and regulating libido

Myth 3: “If you don’t feel symptoms, your estrogen is fine.”
Truth: Some people have no noticeable symptoms until E2 is way out of range, that's why blood tests are so important
(for example, my E2 was at 56 pg/mL and i didn't notice anything)

CONCLUSION
Ais work by lowering estrogen, which delays the closing of your growth plates, giving you more time to grow taller and with that
are a great tool that could give you another 1-6cm, depending on your bone age

(keep in mind that if youre 5'7 at 16 or older with a similar bone age, nothing except LL will bring you to 6'0)

The younger your bone age, the more you can grow through all of this

even tough they are different, the type of Ai you use doesnt really matter
because both have their pros and cons
but understanding how they work and in which ways they are different matters

So, while AIs can help extend your growth window, they’re not some magic pill, get your bloodwork done and dont be a r****d

if i forget anything you want to know, just tell me


other threads i strongly recommend reading

(threads are posted on org)

hope we all ascend

-renos
(milchbibi88)
 
Register to hide this ad
BEST THREAD HERE SO FAR
 
(this is a repost from my org account)
When it comes to heightmaxxing people always recommend the combination of HGH and an AI
but what even are Aromatase Inhibitors?

This guide will teach you everything you need to know about Aromatase inhibitors!
read this guide if you want to gain knowledge about HGH → https://looksmax.org/threads/hgh-101-everything-you-need-to-know.1423722/

THE ROLE OF ESTROGEN WHEN IT COMES TO HEIGHT
Human linear growth occurs at the epiphyseal (growth) plates of long bones, which are zones of cartilage undergoing endochondral ossification.
These plates consist of:
Resting zone: reserves of chondrocytes
Proliferative zone: active cell division
Hypertrophic zone: cell enlargement and mineralization

Bild 2025 08 09 115620286 Photoroom


So, bone lengthening continues until the growth plate closes, which marks the end of height increase.
This closure process is triggered by estrogen

How?
Estrogen closes growth plates by binding to estrogen receptor alpha on chondrocytes, pushing them to mature faster while depleting the reserve of stem-like cells that keep the plate active once these cells mature too quickly, the growth plate runs out of new cells that can make more bone length.

Estrogen also makes the plate release signals that pull in blood vessels, which bring bone building cells
These cells replace the last bits of cartilage with solid bone.
When that happens, the growth plate turns into a thin bony line, and you can’t get any taller.


So make sure your plates are open before you take action
you can confirm this through an x-ray of your hand or knee

1754838598781

The younger your bone age, the more potential you have to grow
ideally it should be younger than 16, but even after that you could grow a few more cm


but once plates are closed, Limb lenghtening is the only way to increase height other than fixing posture and wearing shoe-lifts

WHAT ARE AROMATASE INHIBITORS?

The story starts back in the 1950s and 60s when scientists first figured out how estrogen is made in the body.
They realized that if you could block the aromatase enzyme, you could lower estrogen levels and potentially slow down some type of cancers

In the 1970s, the first aromatase inhibitors were developed. These early drugs, like aminoglutethimide, weren’t very selective and had a lot of side effects.
They worked by binding tightly to the enzyme and basically breaking it, but because they weren’t very specific, patients often had issues.

Then, during the 1980s and early 90s, researchers worked on making better inhibitors.
Nonsteroidal ones came along, such as fadrozole and vorozole, which were safer and more targeted.

The big breakthrough happened in the 1990s: anastrozole, letrozole, and exemestane were invented
These drugs were more effective, had fewer side effects, and became the new standard treatment for hormone-sensitive breast cancer
They’re still widely used today because they work well and patients tolerate them better than older drugs.

Aromatase inhibitors also come to play for treating male hypogonadism or delaying puberty
(and with that being able to grow for a longer period of time)

Aromatase inhibitors are compounds that block or kill the enzyme aromatase, which converts testosterone into estrogen
Aromatase is a cytochrome P450 enzyme, encoded bythe CYP19A1 gene.
It catalyzes the aromatization of the A-ring ofandrogens, specifically:
Testosterone into Estradiol and Androstenedione intoEstrone


(Estrogen refers to a group of hormones that include estradiol, estrone, and estriol, with estradiol being the most potent and prevalent)
By lowering estrogen levels, AIs can delay epiphyseal fusion, extending the window for longitudinal bone growth

The Aromatization Reaction (Biochemistry)

4177656_1717615866064.png

At the molecular level, aromatase performs a three-stepoxidation of the androgen substrate’s A-ring:
Hydroxylation of the 19-methyl group (C19).
Conversion to a formyl group.
Aromatization of the A-ring, forming an aromaticphenol (the hallmark of estrogen).

This process is NADPH-dependent, and localiezd in the endoplasmic reticulum of cells
By taking an aromatase inhibitor we can block this process leading to less estrogen

ANASTROZOLE, LETROZOLE AND EXEMESTANE IN COMPARISON
The main difference is that anastrozole and letrozole are non-steroidal aromatase inhibitors, while exemestane is a steroidal aromatase inhibitor.
Simply put, this means that anastrozole and letrozole anesthetize the aromatase enzyme while exemestane kills the aromatase enzyme
(The enzyme is reproduced by the body)

GENERAL COMPARISON
Property
Anastrozole (Arimidex)
Letrozole (Femara)
Exemestane (Aromasin)
Type
Non-steroidal, reversible
Non-steroidal, reversible
Steroidal, irreversible
Estrogen Suppression
~50–70% (dose dependent)
~80–98% (very potent)
~65–85% (irreversible)
Half-Life
~48 hrs
~40–60 hrs
~24–27 hrs
Rebound Risk
Medium if stopped fast
High (sharp increase)
Low (enzyme destroyed)
Titration Precision
High (easy microdose)
Moderate to difficult
Low (fixed dose tabs)
Bone Impact
Mild (long-term)
moderate to severe
moderate
Lipid impact
Mild, but could affect HDL
Moderate to severe
moderate
Onset of Suppression
~24 hours
Within hours
~24 hours (stronger than Anastrozole)
Peak Suppression
~2–4 days
~2–3 days
~2–3 days

PRICES
Source
Anastrozole Price (1mg)
Letrozole Price (2.5mg)
Exemestane Price (25mg)
Pharma (Brand)
$5–$10
$8–$15
$10–$20
Generic (Indian)
$0.50–$1.50
$1–$3
$1–$4
UGL (Chinese)
$0.20–$0.50
$0.30–$1
$0.30–$1

SIDE EFFECTS
Side Effect
Anastrozole (Arimidex)
Letrozole (Femera)
Exemestane (Aromasin)
Hot flashes
Common
Common
Common
Joint pain
Moderate
Moderate to severe
Mild to moderate
Fatigue
Mild to moderate
Moderate
Mild to moderate
Bone density loss
Mild (long-term use)
More severe if misused
Moderate (monitor needed)
Nausea
Mild
Mild to moderate
Mild
Mood changes
Possible
Possible
Possible
Headache
Occasionally
Occasionally
Occasionally
Increased cholesterol
Mild
Moderate to severe
Moderate
Muscle pain
Mild
Moderate
Mild
Exemestane is harsher on hair because of its androgenic metabolite, 17-β-hydroxyexemestane.
I’d recommend adding something like ru58841 if you choose exemestane.
(That said, hair loss from exemestane only happens if you’re genetically prone to it)


Side effects like losing cognitive abilities only occur when your estrogen is under 10 pg/mL for a longer period of time
this and hair loss were the side effects I was afraid of the most, but as long as you know what youre doing, you don't have to worry about them

Here is a study that proves Ais are safe when it comes to influencing cognitive abilities (if you dont crash E2 ofc)
STUDY https://pubmed.ncbi.nlm.nih.gov/20421333

Also, Ais can increase levels of endogenous Testosterone production in men by 30-60% which is a lot

The biggest downside of non-steroidal Ai's is the possible estrogen rebound

Estrogen rebound is a phenomenon that occurs when the body experiences an increase in estrogen levels after discontinuing or reducing the dosage of aromatase inhibitors like Anastrozole or Letrozole.

This rebound effect happens because these AIs suppress the production of estrogen, but once the AI is stopped, estrogen levels rise temporarily as the body's natural production resumes.

This abrupt rise in the body’s natural production of estrogen could lead to premature closure of growth plates, potentially impacting final height.

Missing a few doses of a non-steroidal Aromatase Inhibitors could cause that, so be careful when using one
rebound can be strongly reduced by tapering off slowly instead of stopping suddenly
but in comparison to exemestane, letrozole and Anastrozole are cheaper and better studied

My personal choice is Exemestane, because it has the least side effects and estrogen rebound isn't a thing
(but like I said, every AI works, just keep E2 at 15-20 pg/mL
and if youre using a non-steroidal one, be careful that you dont forget to take them)


DOSAGE PROTOCOLS AND BLOODWORK

Test your E2 to find the dosage you probably need
1 week into your Ai you should do another blood test to see if you should adjust the dose

You want to Target blood estradiol levels of 15–20 pg/mL and never go under 10 pg/mL
(for reference, normal estradiol levels for teenagers are around 20-50 pg/mL)

If you can't do blood tests, youre basically playing russian roulette, so be careful
in that scenario start a low dose, for example 6,25mg of Exemestane and adjust the dose slowly on how you feel and symptoms you experience

symptoms of low estrogen
Sudden joint pain/dryness

Drop in libido or morning erections
Brain fog, mood drop, irritability
Dry skin or hair shedding increase
Unexplained fatigue
if these occure, lower the dose

symptoms of high estrogen

Puffy face/water retention

Fat gain on hips/chest
Gynecomastia or nipple sensitivity
Emotional volatility or crying easily
Chronic bloating
if these occure you should up the dose

Also, here is an overview, how much different dosages suppress your estrogen

Anastrozole:
0.5 mg → ~50–60% E2 suppression
1 mg → ~80–85% E2 suppression
5 mg → ~85–90% E2 suppression (plateau)
Letrozole:

0.25 mg → ~60–65% E2 suppression
0.5 mg → ~75–80% E2 suppression
1 mg → ~85–90% E2 suppression
2.5 mg → ~90–95% E2 suppression
Exemestane:

6.25 mg → ~30–35% E2 suppression
12.5 mg → ~55–60% E2 suppression
25 mg → ~85–95% E2 suppression
Avoid over suppression (estrogen crash) and Monitor symptoms and do bloodwork.

BlOODWORK

(budget friendly)
Test Estradiol (E2)
Why: Directly shows if your estrogen is in your target range (~15–20 pg/ml).
When:
before the start to calculate the dose you need and then check again 1 week after the start

If everything is correct check 1 month later to see if its stable
then every 8-10 weeks
Total Testosterone + Free Testosterone

Why: AI can raise testosterone; high T can cause secondary effects (acne, aggression, libido swings).
When: Same time as E2 checks.

SHBG (Sex Hormone Binding Globulin)

Why: AI-induced changes in T and E2 affect SHBG, which changes free T availability.
When: every 8-12 weeks Alongside T/E2 checks.

Lipid Panel (Total Cholesterol, LDL, HDL, Triglycerides)

Why: Low E2 can lower HDL and raise LDL → cardiovascular risk.
When: Every 3 months.

Liver Enzymes (ALT, AST)

Why: Ais is metabolized in the liver; rare but possible liver stress.
When: Every 3 months or if symptoms appear.
(important if you drink alcohol)

Bone Health (long-term)

Why: Chronically low E2 can reduce bone density.
When: DEXA scan after 12+ months if running AI long-term.
(optional, but would be good)


simply put together

the baseline test would be:
E2 (sensitive), Total T, Free T, SHBG, Lipid Panel, ALT/AST

around 1 week after AI start:
E2 (sensitive) (optional Total T)

then E2 (sensitive), Total T, Free T, SHBG
every 8-10 weeks and lipids + liver enzymes every 3 months

You can do blood tests in private labs

IMPORTANT NOTES AND TIPS
The time when you take your Ai is not important (should still be around the same time)
But taking your Ai with a meal is
(alternatively, you can take your ai with a tablespoon of olive oil)

Storage:

Dry location with an ideal temperature of 15–25°C and no sun exposure
(just put it in your drawer)

Hormones return to baseline within 2–4 weeks after you stop taking your ai

weird, but don't eat Grapefruits and don't drink Grapefruit Juice

Grapefruit and its juice contain compounds that block the liver enzyme CYP3A4, which helps break down many drugs, including aromatase inhibitors.
This blockage can cause the ai to build up in your blood, and with that increase the risk of side effects

CLINICAL STUDIES OF HEIGHT INCREASE WITH AIS

1754759563737

STUDY https://ijpeonline.biomedcentral.com/articles/10.1186/1687-9856-2015-4

Aromatase inhibitors Alone
Boys with idiopathic short stature or delayed puberty treated with anastrozole (AI) showed around5cm increase in predicted adult height by delaying growth plate closure
STUDY https://pubmed.ncbi.nlm.nih.gov/16189252


Growth Hormone (HGH) Alone:
This study looked at kids with idiopathic short stature (ISS), meaning normal GH levels but short height.
HGH treatment increased adult height by an average of 4–6 cm compared to untreated children.
STUDY https://umraniyepediatri.com/storage/upload/pdfs/1732279204-en.pdf


Combination Therapy (AI + HGH):
combining growth hormone with aromatase inhibitors in adolescent boys with idiopathic short stature led to an average adult height increase of about 6 to 9 cm.
STUDY https://academic.oup.com/jcem/article/110/9/e2871/8125692?login=false


HOPEFUL

Boys grow 2.13 cm in average after the age of 18 without anything
a study shows, that on average, boys grew an additional 2.13 cm between ages 18 and 27, with some increasing by as much as 7 cm
absolutely hopeful study
STUDY https://pubmed.ncbi.nlm.nih.gov/6638938


AIS IN CONTEXT OF BODYBUILDING
1754824211762

i dont want this topic to be left out completely, but i will just cover the most important things

because of higher testosterone levels, the body converts more testosterone to estrogen
Ais can help to control estrogen levels during steroid cycles,
preventing side effects like water retention, bloating, and gynecomastia.

They’re used to maintain a healthy testosterone-to-estrogen balance, which supports better muscle gains, mood, and overall performance.
Additionally, by limiting estrogen, AIs can reduce fat storage and help bodybuilders achieve a leaner, more defined physique.

When Ais come to play in bodybuilding

if your Estradiol is too high and you experience side effects like
-Gyno

-Water retention
-Severe acne
-Mood swings (irritability or depression)

At High Doses or for Estrogen-Sensitive Users
some users don't need one even with +500 mg test a week
while some require an AI even with just 250 mg/week
(At ~500 mg testosterone a week most need an AI)

During Contest Prep
Ais reduce water retention, many bodybuilders use that to achieve a more defined and dryer look

Post-Cycle therapy (PCT)
After a steroid cycle to restore natural testosterone production
Often combined with SERMs (Clomid, Nolvadex)

SPECIAL TOPICS

AI Resistance
true resistance to aromatase inhibitors in men is very rare, but possible
In bodybuilding “resistance” usually means underdosing,
poor absorption of the product, or genetic differences in aromatase activity


In practice:
If estrogen stays high despite seemingly adequate AI dosing,
first rule out fake/underdosed product and high androgen load before assuming true resistance

Many UGL AIs are underdosed

Buy from tested sources (Janoshik reports).
and see how much impact they have on your E2 via bloodwork

Myths about estrogen

Myth 1: “Lower estrogen = more muscle gains.”
Truth: Too little estrogen impairs strength, recovery, joint health, and IGF-1 signaling, all critical for muscle growth.

Myth 2: “Estrogen is bad for men and should be eliminated completely.
Truth: Estrogen plays important roles in men, including bone haelth, brain function, and regulating libido

Myth 3: “If you don’t feel symptoms, your estrogen is fine.”
Truth: Some people have no noticeable symptoms until E2 is way out of range, that's why blood tests are so important
(for example, my E2 was at 56 pg/mL and i didn't notice anything)

CONCLUSION
Ais work by lowering estrogen, which delays the closing of your growth plates, giving you more time to grow taller and with that
are a great tool that could give you another 1-6cm, depending on your bone age

(keep in mind that if youre 5'7 at 16 or older with a similar bone age, nothing except LL will bring you to 6'0)

The younger your bone age, the more you can grow through all of this

even tough they are different, the type of Ai you use doesnt really matter
because both have their pros and cons
but understanding how they work and in which ways they are different matters

So, while AIs can help extend your growth window, they’re not some magic pill, get your bloodwork done and dont be a r****d

if i forget anything you want to know, just tell me


other threads i strongly recommend reading

(threads are posted on org)

hope we all ascend

-renos
(milchbibi88)
mirin guide. @Randomized Shame mustreads?
 
love you bro
i don't really understand why you aren't a mod there anymore, i think you were a great mod
I requested to be unmodded due to a personal issue and then asked to return a few weeks ago. But admins never responded to me or other mods requests done for me.
 
I requested to be unmodded due to a personal issue and then asked to return a few weeks ago. But admins never responded to me or other mods requests done for me.
at least you're still a mod here, but i understand that this sucks
 
(this is a repost from my org account)
When it comes to heightmaxxing people always recommend the combination of HGH and an AI
but what even are Aromatase Inhibitors?

This guide will teach you everything you need to know about Aromatase inhibitors!
read this guide if you want to gain knowledge about HGH → https://looksmax.org/threads/hgh-101-everything-you-need-to-know.1423722/

THE ROLE OF ESTROGEN WHEN IT COMES TO HEIGHT
Human linear growth occurs at the epiphyseal (growth) plates of long bones, which are zones of cartilage undergoing endochondral ossification.
These plates consist of:
Resting zone: reserves of chondrocytes
Proliferative zone: active cell division
Hypertrophic zone: cell enlargement and mineralization

Bild 2025 08 09 115620286 Photoroom


So, bone lengthening continues until the growth plate closes, which marks the end of height increase.
This closure process is triggered by estrogen

How?
Estrogen closes growth plates by binding to estrogen receptor alpha on chondrocytes, pushing them to mature faster while depleting the reserve of stem-like cells that keep the plate active once these cells mature too quickly, the growth plate runs out of new cells that can make more bone length.

Estrogen also makes the plate release signals that pull in blood vessels, which bring bone building cells
These cells replace the last bits of cartilage with solid bone.
When that happens, the growth plate turns into a thin bony line, and you can’t get any taller.


So make sure your plates are open before you take action
you can confirm this through an x-ray of your hand or knee

1754838598781

The younger your bone age, the more potential you have to grow
ideally it should be younger than 16, but even after that you could grow a few more cm


but once plates are closed, Limb lenghtening is the only way to increase height other than fixing posture and wearing shoe-lifts

WHAT ARE AROMATASE INHIBITORS?

The story starts back in the 1950s and 60s when scientists first figured out how estrogen is made in the body.
They realized that if you could block the aromatase enzyme, you could lower estrogen levels and potentially slow down some type of cancers

In the 1970s, the first aromatase inhibitors were developed. These early drugs, like aminoglutethimide, weren’t very selective and had a lot of side effects.
They worked by binding tightly to the enzyme and basically breaking it, but because they weren’t very specific, patients often had issues.

Then, during the 1980s and early 90s, researchers worked on making better inhibitors.
Nonsteroidal ones came along, such as fadrozole and vorozole, which were safer and more targeted.

The big breakthrough happened in the 1990s: anastrozole, letrozole, and exemestane were invented
These drugs were more effective, had fewer side effects, and became the new standard treatment for hormone-sensitive breast cancer
They’re still widely used today because they work well and patients tolerate them better than older drugs.

Aromatase inhibitors also come to play for treating male hypogonadism or delaying puberty
(and with that being able to grow for a longer period of time)

Aromatase inhibitors are compounds that block or kill the enzyme aromatase, which converts testosterone into estrogen
Aromatase is a cytochrome P450 enzyme, encoded bythe CYP19A1 gene.
It catalyzes the aromatization of the A-ring ofandrogens, specifically:
Testosterone into Estradiol and Androstenedione intoEstrone


(Estrogen refers to a group of hormones that include estradiol, estrone, and estriol, with estradiol being the most potent and prevalent)
By lowering estrogen levels, AIs can delay epiphyseal fusion, extending the window for longitudinal bone growth

The Aromatization Reaction (Biochemistry)

4177656_1717615866064.png

At the molecular level, aromatase performs a three-stepoxidation of the androgen substrate’s A-ring:
Hydroxylation of the 19-methyl group (C19).
Conversion to a formyl group.
Aromatization of the A-ring, forming an aromaticphenol (the hallmark of estrogen).

This process is NADPH-dependent, and localiezd in the endoplasmic reticulum of cells
By taking an aromatase inhibitor we can block this process leading to less estrogen

ANASTROZOLE, LETROZOLE AND EXEMESTANE IN COMPARISON
The main difference is that anastrozole and letrozole are non-steroidal aromatase inhibitors, while exemestane is a steroidal aromatase inhibitor.
Simply put, this means that anastrozole and letrozole anesthetize the aromatase enzyme while exemestane kills the aromatase enzyme
(The enzyme is reproduced by the body)

GENERAL COMPARISON
Property
Anastrozole (Arimidex)
Letrozole (Femara)
Exemestane (Aromasin)
Type
Non-steroidal, reversible
Non-steroidal, reversible
Steroidal, irreversible
Estrogen Suppression
~50–70% (dose dependent)
~80–98% (very potent)
~65–85% (irreversible)
Half-Life
~48 hrs
~40–60 hrs
~24–27 hrs
Rebound Risk
Medium if stopped fast
High (sharp increase)
Low (enzyme destroyed)
Titration Precision
High (easy microdose)
Moderate to difficult
Low (fixed dose tabs)
Bone Impact
Mild (long-term)
moderate to severe
moderate
Lipid impact
Mild, but could affect HDL
Moderate to severe
moderate
Onset of Suppression
~24 hours
Within hours
~24 hours (stronger than Anastrozole)
Peak Suppression
~2–4 days
~2–3 days
~2–3 days

PRICES
Source
Anastrozole Price (1mg)
Letrozole Price (2.5mg)
Exemestane Price (25mg)
Pharma (Brand)
$5–$10
$8–$15
$10–$20
Generic (Indian)
$0.50–$1.50
$1–$3
$1–$4
UGL (Chinese)
$0.20–$0.50
$0.30–$1
$0.30–$1

SIDE EFFECTS
Side Effect
Anastrozole (Arimidex)
Letrozole (Femera)
Exemestane (Aromasin)
Hot flashes
Common
Common
Common
Joint pain
Moderate
Moderate to severe
Mild to moderate
Fatigue
Mild to moderate
Moderate
Mild to moderate
Bone density loss
Mild (long-term use)
More severe if misused
Moderate (monitor needed)
Nausea
Mild
Mild to moderate
Mild
Mood changes
Possible
Possible
Possible
Headache
Occasionally
Occasionally
Occasionally
Increased cholesterol
Mild
Moderate to severe
Moderate
Muscle pain
Mild
Moderate
Mild
Exemestane is harsher on hair because of its androgenic metabolite, 17-β-hydroxyexemestane.
I’d recommend adding something like ru58841 if you choose exemestane.
(That said, hair loss from exemestane only happens if you’re genetically prone to it)


Side effects like losing cognitive abilities only occur when your estrogen is under 10 pg/mL for a longer period of time
this and hair loss were the side effects I was afraid of the most, but as long as you know what youre doing, you don't have to worry about them

Here is a study that proves Ais are safe when it comes to influencing cognitive abilities (if you dont crash E2 ofc)
STUDY https://pubmed.ncbi.nlm.nih.gov/20421333

Also, Ais can increase levels of endogenous Testosterone production in men by 30-60% which is a lot

The biggest downside of non-steroidal Ai's is the possible estrogen rebound

Estrogen rebound is a phenomenon that occurs when the body experiences an increase in estrogen levels after discontinuing or reducing the dosage of aromatase inhibitors like Anastrozole or Letrozole.

This rebound effect happens because these AIs suppress the production of estrogen, but once the AI is stopped, estrogen levels rise temporarily as the body's natural production resumes.

This abrupt rise in the body’s natural production of estrogen could lead to premature closure of growth plates, potentially impacting final height.

Missing a few doses of a non-steroidal Aromatase Inhibitors could cause that, so be careful when using one
rebound can be strongly reduced by tapering off slowly instead of stopping suddenly
but in comparison to exemestane, letrozole and Anastrozole are cheaper and better studied

My personal choice is Exemestane, because it has the least side effects and estrogen rebound isn't a thing
(but like I said, every AI works, just keep E2 at 15-20 pg/mL
and if youre using a non-steroidal one, be careful that you dont forget to take them)


DOSAGE PROTOCOLS AND BLOODWORK

Test your E2 to find the dosage you probably need
1 week into your Ai you should do another blood test to see if you should adjust the dose

You want to Target blood estradiol levels of 15–20 pg/mL and never go under 10 pg/mL
(for reference, normal estradiol levels for teenagers are around 20-50 pg/mL)

If you can't do blood tests, youre basically playing russian roulette, so be careful
in that scenario start a low dose, for example 6,25mg of Exemestane and adjust the dose slowly on how you feel and symptoms you experience

symptoms of low estrogen
Sudden joint pain/dryness

Drop in libido or morning erections
Brain fog, mood drop, irritability
Dry skin or hair shedding increase
Unexplained fatigue
if these occure, lower the dose

symptoms of high estrogen

Puffy face/water retention

Fat gain on hips/chest
Gynecomastia or nipple sensitivity
Emotional volatility or crying easily
Chronic bloating
if these occure you should up the dose

Also, here is an overview, how much different dosages suppress your estrogen

Anastrozole:
0.5 mg → ~50–60% E2 suppression
1 mg → ~80–85% E2 suppression
5 mg → ~85–90% E2 suppression (plateau)
Letrozole:

0.25 mg → ~60–65% E2 suppression
0.5 mg → ~75–80% E2 suppression
1 mg → ~85–90% E2 suppression
2.5 mg → ~90–95% E2 suppression
Exemestane:

6.25 mg → ~30–35% E2 suppression
12.5 mg → ~55–60% E2 suppression
25 mg → ~85–95% E2 suppression
Avoid over suppression (estrogen crash) and Monitor symptoms and do bloodwork.

BlOODWORK

(budget friendly)
Test Estradiol (E2)
Why: Directly shows if your estrogen is in your target range (~15–20 pg/ml).
When:
before the start to calculate the dose you need and then check again 1 week after the start

If everything is correct check 1 month later to see if its stable
then every 8-10 weeks
Total Testosterone + Free Testosterone

Why: AI can raise testosterone; high T can cause secondary effects (acne, aggression, libido swings).
When: Same time as E2 checks.

SHBG (Sex Hormone Binding Globulin)

Why: AI-induced changes in T and E2 affect SHBG, which changes free T availability.
When: every 8-12 weeks Alongside T/E2 checks.

Lipid Panel (Total Cholesterol, LDL, HDL, Triglycerides)

Why: Low E2 can lower HDL and raise LDL → cardiovascular risk.
When: Every 3 months.

Liver Enzymes (ALT, AST)

Why: Ais is metabolized in the liver; rare but possible liver stress.
When: Every 3 months or if symptoms appear.
(important if you drink alcohol)

Bone Health (long-term)

Why: Chronically low E2 can reduce bone density.
When: DEXA scan after 12+ months if running AI long-term.
(optional, but would be good)


simply put together

the baseline test would be:
E2 (sensitive), Total T, Free T, SHBG, Lipid Panel, ALT/AST

around 1 week after AI start:
E2 (sensitive) (optional Total T)

then E2 (sensitive), Total T, Free T, SHBG
every 8-10 weeks and lipids + liver enzymes every 3 months

You can do blood tests in private labs

IMPORTANT NOTES AND TIPS
The time when you take your Ai is not important (should still be around the same time)
But taking your Ai with a meal is
(alternatively, you can take your ai with a tablespoon of olive oil)

Storage:

Dry location with an ideal temperature of 15–25°C and no sun exposure
(just put it in your drawer)

Hormones return to baseline within 2–4 weeks after you stop taking your ai

weird, but don't eat Grapefruits and don't drink Grapefruit Juice

Grapefruit and its juice contain compounds that block the liver enzyme CYP3A4, which helps break down many drugs, including aromatase inhibitors.
This blockage can cause the ai to build up in your blood, and with that increase the risk of side effects

CLINICAL STUDIES OF HEIGHT INCREASE WITH AIS

1754759563737

STUDY https://ijpeonline.biomedcentral.com/articles/10.1186/1687-9856-2015-4

Aromatase inhibitors Alone
Boys with idiopathic short stature or delayed puberty treated with anastrozole (AI) showed around5cm increase in predicted adult height by delaying growth plate closure
STUDY https://pubmed.ncbi.nlm.nih.gov/16189252


Growth Hormone (HGH) Alone:
This study looked at kids with idiopathic short stature (ISS), meaning normal GH levels but short height.
HGH treatment increased adult height by an average of 4–6 cm compared to untreated children.
STUDY https://umraniyepediatri.com/storage/upload/pdfs/1732279204-en.pdf


Combination Therapy (AI + HGH):
combining growth hormone with aromatase inhibitors in adolescent boys with idiopathic short stature led to an average adult height increase of about 6 to 9 cm.
STUDY https://academic.oup.com/jcem/article/110/9/e2871/8125692?login=false


HOPEFUL

Boys grow 2.13 cm in average after the age of 18 without anything
a study shows, that on average, boys grew an additional 2.13 cm between ages 18 and 27, with some increasing by as much as 7 cm
absolutely hopeful study
STUDY https://pubmed.ncbi.nlm.nih.gov/6638938


AIS IN CONTEXT OF BODYBUILDING
1754824211762

i dont want this topic to be left out completely, but i will just cover the most important things

because of higher testosterone levels, the body converts more testosterone to estrogen
Ais can help to control estrogen levels during steroid cycles,
preventing side effects like water retention, bloating, and gynecomastia.

They’re used to maintain a healthy testosterone-to-estrogen balance, which supports better muscle gains, mood, and overall performance.
Additionally, by limiting estrogen, AIs can reduce fat storage and help bodybuilders achieve a leaner, more defined physique.

When Ais come to play in bodybuilding

if your Estradiol is too high and you experience side effects like
-Gyno

-Water retention
-Severe acne
-Mood swings (irritability or depression)

At High Doses or for Estrogen-Sensitive Users
some users don't need one even with +500 mg test a week
while some require an AI even with just 250 mg/week
(At ~500 mg testosterone a week most need an AI)

During Contest Prep
Ais reduce water retention, many bodybuilders use that to achieve a more defined and dryer look

Post-Cycle therapy (PCT)
After a steroid cycle to restore natural testosterone production
Often combined with SERMs (Clomid, Nolvadex)

SPECIAL TOPICS

AI Resistance
true resistance to aromatase inhibitors in men is very rare, but possible
In bodybuilding “resistance” usually means underdosing,
poor absorption of the product, or genetic differences in aromatase activity


In practice:
If estrogen stays high despite seemingly adequate AI dosing,
first rule out fake/underdosed product and high androgen load before assuming true resistance

Many UGL AIs are underdosed

Buy from tested sources (Janoshik reports).
and see how much impact they have on your E2 via bloodwork

Myths about estrogen

Myth 1: “Lower estrogen = more muscle gains.”
Truth: Too little estrogen impairs strength, recovery, joint health, and IGF-1 signaling, all critical for muscle growth.

Myth 2: “Estrogen is bad for men and should be eliminated completely.
Truth: Estrogen plays important roles in men, including bone haelth, brain function, and regulating libido

Myth 3: “If you don’t feel symptoms, your estrogen is fine.”
Truth: Some people have no noticeable symptoms until E2 is way out of range, that's why blood tests are so important
(for example, my E2 was at 56 pg/mL and i didn't notice anything)

CONCLUSION
Ais work by lowering estrogen, which delays the closing of your growth plates, giving you more time to grow taller and with that
are a great tool that could give you another 1-6cm, depending on your bone age

(keep in mind that if youre 5'7 at 16 or older with a similar bone age, nothing except LL will bring you to 6'0)

The younger your bone age, the more you can grow through all of this

even tough they are different, the type of Ai you use doesnt really matter
because both have their pros and cons
but understanding how they work and in which ways they are different matters

So, while AIs can help extend your growth window, they’re not some magic pill, get your bloodwork done and dont be a r****d

if i forget anything you want to know, just tell me


other threads i strongly recommend reading

(threads are posted on org)

hope we all ascend

-renos
(milchbibi88)
😍😍😍😍 Holy this thread is just beautiful (I'm also envious)
 
yo wsg my n***a, this ru58841 from org

with using AIs im concerned about the retards who nuke there estrogen to zero

estrogen is neuro and cardio protective so blocking it will fuck your health

also estrogen is needed for the conversion of gh to igf1 (thats why bodybuilders say estrogen is anabolic)
 
yo wsg my n***a, this ru58841 from org

with using AIs im concerned about the retards who nuke there estrogen to zero

estrogen is neuro and cardio protective so blocking it will fuck your health

also estrogen is needed for the conversion of gh to igf1 (thats why bodybuilders say estrogen is anabolic)
of course, it should be put to around 14-15 pg/ml for optimal hieght
 

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