A huge concern for many individuals before getting on Finasteride, and while they are actually on it, is the possibility of getting Gynecomastia (gyno).

What Is Gynecomastia

Gynecomastia is swollen male breast tissue that develops in boys or men.

Gynecomastia is also commonly referred to as “man boobs”, or “bitch tits”.

What Causes Gynecomastia

Gynecomastia is typically the result of chronically elevated Estrogen levels.

Gynecomastia can also develop in men when there is a decrease in Free Testosterone, causing a hormonal imbalance via a state of Estrogen dominance.

There is a certain amount of Estrogen a man needs to function optimally, and despite what many believe, having 0 Estrogen would actually screw you up and lead to a huge array of negative side effects, so don’t go Gung Ho popping Letrozole like candy thinking it is the solution here.

The longer someone’s Estrogen is left out of range on the high end, the more breast tissue development will occur, and the amount that occurs is relative to how high those Estrogen levels are above the normal range.

How Does Finasteride Cause Gynecomastia

I get really annoyed when I hear people talking about how Finasteride causes Gyno and to stay away because it will give you bitch tits, and so on and so forth.

If you get Gyno from Propecia/Finasteride, it is literally the result of poor hormone management, and nothing else.

This is what you need to understand.

Read this carefully.

This is exactly what happens when you take Finasteride in steps:

• Finasteride inhibits the enzyme 5-alpha reductase, which is the enzyme that regulates the conversion of Testosterone into the far more androgenic hormone dihydrotestosterone (DHT).
• Dihydrotestosterone(DHT), or 5α-dihydrotestosterone (5α-DHT) is far more potent of an androgen than Testosterone, and when it binds to the hair follicles it can cause severe miniaturization of those hair follicles, which is the primary mechanism behind what causes permanent hair loss.
• When you inhibit the conversion of Testosterone to DHT with Finasteride (the point of using it for hair loss prevention purposes), you are left with more circulating Testosterone because it has been inhibited from converting into DHT to a significant extent (by Finasteride).
• Testosterone doesn’t just convert to DHT, it also aromatizes into Estrogen, and when you have more Testosterone circulating in the body that means there is more Testosterone aromatizing into Estrogen as well.
• The official brochure from the manufacturer of Propecia, Merck, states that “mean circulating levels of testosterone and estradiol were increased by approximately 15%“. Estradiol is another word for Estrogen.

So, you have less DHT in your body, but you now have a bit more Testosterone and Estrogen.

And remember at the start of the article, chronically elevated Estrogen will lead to the development of breast tissue.

How To Know If Your Estrogen Levels Are Elevated Enough To Induce Gynecomastia

If you don’t have baseline blood work before taking a drug that affects your hormonal profile significantly, your doctor has already failed you, and this is why you need to know WTF you are doing before you just trust that every doctor knows how hormones work.

To be frank, the vast majority of doctors have zero clue what they are doing when it comes to hormone management, so you need to understand how to read your blood work yourself inside out.

For your Estrogen levels in particular, the standard reference range (what is considered “normal”) in men is 15-40 pg/mL.

The reference range on your blood work will very likely differ slightly, and may even be in a different unit of measurement, as every country has their own guidelines dictating what a “normal male” should be at.

This is what you need to know and remember:

The golden sweet spot for Estrogen levels in men is between 20-30 pg/mL.

If you keep your Estrogen in that range forever, you will never get Gyno from Finasteride.

If you prevent your Estrogen from getting out of range, it is physically impossible to start developing breast tissue from Finasteride usage.

This is assuming that other endogenous hormones are also at healthy levels in the body, but I will delve into that later in the article as that is a less common occurrence.

So, the first thing you need to do is go get a blood test.

See what your Estrogen levels are, and make sure you get a copy of the test for you to analyze yourself, don’t let a doctor relay it back to you and just tell you “it’s fine,” because half the time they haven’t the faintest idea what “fine” really is.

They’ll tell you your Testosterone levels are “fine” even if they are on the very lowest end of “normal”, when in reality that would only be “normal” for someone who is on the brink of dying in old age.

Anyways, rant over.

Get your blood work done.

Get a Sensitive Estradiol Assay, and if the results aren't in pg/mL, use this Estradiol conversion calculator to convert it into pg/mL.

If your levels are above 40 pg/mL, I would advise using an Aromatase Inhibitor to lower those levels.

What Are Aromatase Inhibitors

Aromatase Inhibitors (AIs) are drugs that were designed to treat of breast cancer in postmenopausal women and Gynecomastia in men.

Aromatase Inhibitors inhibit the action of the enzyme aromatase.

As mentioned, the Testosterone in your body aromatizes into Estrogen, and it is accomplished via the enzyme aromatase.

When you use an Aromatase Inhibitor, you quite literally, inhibit the enzyme aromatase from doing its’ job, thereby allowing you to reduce the amount of aromatization occurring in your body, and lowering circulating Estrogen levels.

So, if you are already out of range, you should be on an AI.

If you are on the cusp of being out of range and you hop on Finasteride which raises your Estrogen levels a decent amount, you will likely need an AI.

If your Estrogen levels are already in range while you are on Finasteride, then you DO NOT need to worry about getting Gyno.

The goal is to keep Estrogen in the sweet spot forever. If it never gets elevated, you cannot get Finasteride induced Gyno, end of story.

I believe the sweet spot is 20-30 pg/mL and that is where I keep my levels year round to not only feel amazing, but prevent any unwanted side effects or impairment to my physiological functions and quality of life that could occur from Estrogen levels that are too low, or too high.

Which Aromatase Inhibitor Should I Use For Estrogen Management

To save you a bunch of time researching these, and this is something you will only learn from personal experience, this is the breakdown of all of the most relevant AI’s you will need to know about.

Which Aromatase Inhibitor Is Weakest And Which Is The Strongest:

• Arimistane (greatest margin of error, weakest aromatase inhibitor)
• Aromasin (high margin of error, fairly strong aromatase inhibitor)
• Arimidex (low margin of error, fairly easy to crash Estrogen unless on a high dose of aromatizing compounds, very strong aromatase inhibitor)
• Letrozole (minimal margin of error, VERY easy to crash Estrogen by accident, even on tons of aromatizing compounds, the strongest aromatase inhibitor)

If you aren’t on a bunch of aromatizing drugs (like using exogenous Testosterone or other aromatizing Steroids), you will more than likely only need Arimistane or Aromasin.

I’d recommend a low dose of Aromasin.

Note, a LOW dose of Aromasin.

If you’re not taking a bunch of drugs that aromatize, and you’re just dealing with slight systemic elevation of Estrogen from Finasteride usage, you DO NOT need a crazy dosage.

The dosage will depend entirely on your blood work, and there is no set in stone “use this dose and you will get to 20-30 pg/mL Estrogen”.

No, it doesn’t work like that.

You need to experiment, start low, and taper up slowly as necessary with constant blood work evaluation.

If you are only a few pg/mL above 40, you don’t need to be hitting yourself with 12.5 mg everyday.

If your Estrogen levels are closer to 100 though, then that may not be the case and you may need a dose like that.

It’s all going to be individually dependent.

But what I would do, in general, as you likely don’t have severely elevated Estrogen if you aren’t on additional steroids, is to start with 12.5 mg Aromasin (also called Exemestane) once on Monday, and once on Thursday.

This is conservative, and likely won’t crash your levels.

Get bloods done afterwards, and see where your Estrogen levels lie.

If they are out of range still, gauge how much they have decreased, and then make a judgment call on how many more days of dosing to add.

If your levels were 60 pg/mL and you took 12.5 mg Aromasin twice per week and it brought them down to 43 for example, then you might want to try 12.5 mg Aromasin once every other day.

These are all hypothetical examples of course, but that is the approach I’d take.

Once your Estrogen levels are brought down into range, you will never have to worry about Gynecomastia from Finasteride again.

Getting Gynecomastia Even With Low Estrogen Levels On Finasteride

This is a rarer occurrence, but there is evidence to support that some individuals experience a reduction in Free Testosterone while on Finasteride, despite Total Testosterone increasing by roughly 15%.

Free Testosterone is actually the marker we care about, as that is unbound Testosterone that we can utilize, as opposed to Total Testosterone which is simply the total amount of Testosterone in the body, including the majority of it which is bound by Sex Hormone Binding Globulin (SHBG) and Albumin.

Free Testosterone is the only biologically active Testosterone in the body we can actually make use of.

Even if Total Testosterone goes up, if Free Testosterone doesn't go up in parallel to it, you just have a higher level of present Testosterone in the body, but none of that is actually biologically active.

In the majority of Finasteride's clinical studies, there was no effect on SHBG, and Total Testosterone and Estrogen increased by approximately 15% [R, R].

However, in some studies there was a noted drop of Free Testosterone, despite the increase in Total Testosterone [R, R].

A drop in biologically active Free Testosterone with a concurrent 15% increase in Estrogen levels in the body can lead to a hormonal imbalance.

Anytime the tightly regulated balance of Testosterone:Estrogen is disrupted and Estrogen is too high relative to Testosterone than it should be, a man becomes more prone to developing Gynecomastia.

It doesn't matter if that imbalance occurs via an increase in Estrogen (the most common way gyno occurs), or a decrease in Free Testosterone relative to Estrogen.

If the body is in a state of Estrogen dominance, gyno can develop.

DHT antagonizes SHBG and lowers it, which is partially why men will use DHT derivatives like Proviron to improve their Free Testosterone levels alongside their Testosterone replacement therapy (TRT), and the data supports that lowering systemic DHT (what Finasteride does) would theoretically increase SHBG [R].

When SHBG increases, that increases the amount of Total Testosterone that becomes bound and is no longer bioactive or usable, consequently lowering Free Testosterone.

If you fall into the unfortunate predicament of still experiencing Gyno development even with Estradiol levels at 20-30 pg/mL, you will still likely be able to prevent Gyno with an AI, as AI's will decrease SHBG and Estrogen in the body, while increasing Total Testosterone and Free Testosterone [R].

You just have to be careful about potentially creating low Estrogen side effects, as Estrogen is still a necessary hormone in the male body to mediate other physiological functions.

Long term AI usage also has its own potential implications in regards to how it affects lipid levels in the body.

Frankly, an AI is only a quick first line of defense to get your gyno under control immediately.

You should seriously evaluate your diet and lifestyle choices as there are ways to inhibit aromatase naturally that are sustainable long term without the deleterious outcomes long-term AI use could have.

AI's aren't healthy to use, so ideally you would want to transition off of it once you get your diet, lifestyle, and/or body composition in check to prevent Estrogen dominance from being an issue.

If for some reason you cannot prevent Gyno onset with an AI by manually keeping your levels close to 20 pg/mL (rare, but I've heard of some anecdotal cases of this), you will have to consider incorporating SERMs like Nolvadex or Raloxifene to prevent Estrogen from binding to the receptors in breast tissue, which would then make it physically impossible to exacerbate Gynecomastia.

Raloxifene is superior to Nolvadex in my personal opinion, and should be the SERM of choice for those who fall into that scenario.

Disclaimer: The information included in this article is intended for entertainment and informational purposes only. It is not intended nor implied to be a substitute for professional medical advice.