Which Steroids Don’t Aromatize and Cause Gyno

  • By: Dave Moffat
  • Date: July 10, 2023
Which Steroids Don't Aromatize

Steroids have long been a subject of interest and controversy in the fitness and bodybuilding worlds. They offer significant performance and physique-enhancing benefits but also come with potential side effects.

One of these side effects is aromatization the conversion of steroids into estrogen by the enzyme aromatase.

This process can lead to undesirable effects like water retention and gynecomastia (male breast enlargement).

However, not all steroids undergo this process. Non-aromatizing steroids, as their name suggests, do not convert into estrogen, thereby avoiding these side effects.

This article will delve into the world of non-aromatizing steroids, exploring what they are, popular examples, their potential side effects, and their risks.

Our goal is to provide you with comprehensive information to make informed decisions about steroid use.

So, whether you’re a seasoned bodybuilder or just beginning your fitness journey, read on to learn more about non-aromatizing steroids.

Aromatization: A Brief Overview

Aromatization is a biological process that occurs in the human body, where an enzyme known as aromatase converts androgens (male hormones) into estrogens (female hormones). This process is crucial for maintaining the balance of sex hormones in both men and women.

Androgens such as testosterone and androstenedione are substrates for the aromatase enzyme. When these androgens enter cells, aromatase, located in the endoplasmic reticulum of the cell, converts them into the female hormones estradiol and estrone, respectively.

While some estrogen is necessary in males for functions like bone health and brain function, excessive amounts can lead to negative side effects. This is particularly relevant in the context of anabolic steroid use. Some anabolic steroids, which are derivatives of testosterone, can be converted into estrogen through the aromatization process.

This is where the aromatase enzyme plays a critical role. It’s responsible for the conversion or aromatization of these steroids. For example, when an individual takes a steroid like testosterone enanthate, the aromatase enzyme can convert it into estradiol.

The higher the level of aromatase activity or the greater the amount of aromatizable androgens, the greater the conversion into estrogen. This can lead to an imbalance in hormone levels and result in side effects such as water retention, fat gain, and gynecomastia.

It’s important to note that not all steroids are susceptible to this conversion. Non-aromatizing steroids, which we will explore in the next sections, are immune to the effects of the aromatase enzyme, making them an attractive option for those looking to avoid the side effects of aromatization.

Non-Aromatizing Steroids: What Are They?

Non-aromatizing steroids are a category of anabolic steroids that do not convert into estrogen in the body, hence the term ‘non-aromatizing’. As a result, when metabolized, they do not produce the female hormone estrogen due to a lack of aromatase enzyme processing.

Some examples of non-aromatizing steroids include Anavar (Oxandrolone), Winstrol (Stanozolol), Masteron (Drostanolone), and Trenbolone. These steroids are typically used for their muscle-building benefits without the risk of certain side effects associated with high estrogen levels.

The preference for non-aromatizing steroids among some athletes and bodybuilders stems from the desire to avoid these estrogen-related side effects.

When anabolic steroids aromatize, they can lead to issues such as water retention, fat gain, and gynecomastia (male breast enlargement). These side effects can be particularly problematic for bodybuilders aiming for a lean, muscular physique.

High estrogen levels can also lead to other health concerns, such as high blood pressure and cholesterol imbalances. By using non-aromatizing steroids, individuals can reap the performance-enhancing benefits of steroids while minimizing these potential side effects.

However, it’s important to note that while non-aromatizing steroids reduce the risk of estrogenic side effects, they may have other side effects and risks, which we will explore later in this article.

Popular Non-Aromatizing Steroids

Non-aromatizing steroids are popular among athletes and bodybuilders due to their ability to provide muscle mass gains and performance enhancement without converting into estrogen in the body.

This means they don’t typically lead to estrogen-related side effects like water retention and gynecomastia (male breast enlargement).

Here’s information about four popular non-aromatizing steroids:

  • Anavar (Oxandrolone): Anavar is a mild anabolic steroid known for its low androgenic activity. It’s often used during cutting cycles to maintain lean muscle mass while losing body fat. Anavar promotes increased strength, improved muscle density, and enhanced recovery. However, it can cause side effects like hair loss and acne in predisposed individuals.
Legal Anavar Alternative
Anvarol By CrazyBulk

Benefits of Anvarol

  • Gives explosive power & strength
  • Incinerate visceral & subcutaneous fat
  • Preserve lean muscle when cutting calories
  • Improved muscle hardness & density
  • A safe and legal alternative to Anavar


  • Winstrol (Stanozolol): Winstrol is another popular non-aromatizing steroid, often used during cutting cycles to preserve lean muscle mass and enhance muscular definition. It’s also known for promoting strength and endurance without unwanted water retention. Despite its benefits, Winstrol can have negative effects on cholesterol levels and liver health.
Legal Winstrol Alternative
Winsol by Crazy Bulk

Benefits of Winsol

  • Winsol preserves lean muscle mass whilst stripping fat
  • Gives you a ripped competition & beach physique
  • Rock-hard defined muscles
  • Enhanced vascularity
  • Super strength & endurance
  • Maximum power, speed & agility for running



  • Masteron (Drostanolone): Masteron is known for its strong anti-estrogenic properties, making it a popular choice among bodybuilders looking to avoid water retention and achieve a hardened and defined look. It’s typically used during the final weeks leading up to a competition. Side effects can include hair loss, acne, and aggression.
Legal Testosterone Alternative
  • Boosts testosterone production
  • Increases free testosterone levels
  • Slows conversion of testosterone to estrogen
  • 100% Safe & Natural
  • Fast, Noticeable Results


  • Trenbolone: Trenbolone is one of the most potent anabolic steroids available. It’s known for its ability to promote significant muscle growth, enhance fat loss, and increase strength. However, despite not aromatizing, Trenbolone can still lead to estrogen-like side effects due to its progestational activity. It can also have significant impacts on mood and cardiovascular health.
Legal Trenbolone Alternative
Trenorol by CrazyBulk

Benefits of Trenorol

  • Shred fat without losing mass
  • Super strength & stamina
  • Amazing physical conditioning
  • Enhanced vascularity
  • Helps reduce recovery time between workouts without sacrificing muscle mass


Weighing the Pros and Cons: Side Effects and Risks

When it comes to using non-aromatizing steroids, it’s important to consider both the potential benefits and risks. While these substances can provide significant muscle growth and performance enhancement, they also come with a range of common side effects and potential risks that should not be ignored.

Common Side Effects

Non-aromatizing steroids are generally well-tolerated compared to their aromatizing counterparts, but they can still cause a variety of side effects. These include:

  • Androgenic Effects: Despite their low estrogenic activity, non-aromatizing steroids can still cause androgenic side effects such as acne, hair loss, and increased body hair growth, particularly in individuals who are genetically predisposed to these conditions.
  • Cardiovascular Issues: Steroids like Winstrol and Trenbolone can have negative effects on cholesterol levels, potentially increasing the risk of heart disease over time. They can also lead to increased blood pressure.
  • Mood Changes: Some users report mood changes, including increased aggression and irritability, particularly with potent steroids like Trenbolone.
  • Liver Damage: Oral steroids like Anavar and Winstrol can be hard on the liver, particularly when used in high doses or for extended periods.

Potential Risks

In addition to these common side effects, there are also several potential risks associated with non-aromatizing steroid use:

  • Dependency and Addiction: While less common than with other substances, it is possible to become psychologically dependent on steroids, leading to withdrawal symptoms when usage is stopped.
  • Long-Term Health Consequences: Prolonged use of anabolic steroids can lead to long-term health issues such as heart disease, liver damage, and fertility issues.
  • Legal and Ethical Considerations: In many jurisdictions, it’s illegal to use anabolic steroids without a prescription. There are also ethical considerations around their use in competitive sports.

Steroids Notorious for Causing Gynecomastia

Gynecomastia, also known as gyno, is a common side effect of steroid use. An imbalance of hormones in the body, particularly when there is an excess of estrogen, can cause this condition, which causes breast tissue enlargement in males.

Here are a few steroids notorious for causing gyno:

  • Dianabol (Methandrostenolone): Dianabol is one of the most well-known oral anabolic steroids and is notorious for its propensity to cause gynecomastia because it aromatizes easily into estrogen.
Legal Dianabol Alternative
D-Bal by Crazy Bulk

Benefits of D-Bal

  • Increases muscle mass while reducing recovery time
  • Helps increase the amount of oxygen your body can utilize during workouts
  • A safe and legal alternative to Dianabol
  • Contains Ashwagandha which has been proven to improve overall performance
  • Fast muscle gains
  • Super strength and stamina


  • Anadrol (Oxymetholone): Anadrol is another powerful steroid that can cause gyno. Despite not being known to directly convert to estrogen, it’s believed to have progestogenic activity, which can stimulate the estrogenic pathway.
Anadrole by Crazy Bulk

Benefits of Anadrole

  • Mega increase in muscle mass
  • Super strength & stamina
  • Massive pumps & vascularity
  • Ultra-lean ripped physique
  • Intense energy & endurance for workouts


  • Deca-Durabolin (Nandrolone Decanoate): While Deca-Durabolin has a low rate of aromatization, it has strong progestogenic activity which can increase the risk of developing gyno.
Legal Deca Durabolin Alternative
DecaDuro by CrazyBulk

Benefits of DecaDuro

  • Explosive power and strength for runners during competitions
  • Preserve lean muscle whilst reducing body fat
  • Relieve joint & tendon pain
  • Fast muscle recovery after grueling workouts
  • Testosterone: All forms of exogenous testosterone can convert to estrogen in the body through the process of aromatization, thus increasing the risk of gynecomastia.
Legal Testosterone Alternative
Testo-Max by Crazy Bulk
  • EXTREME Strength
  • Enhances Performance
  • Reduces Recovery Time
  • Pre-Breakfast


It’s important to note that not everyone who uses these steroids will develop gynecomastia. Factors such as genetics, dosage, duration of use, and the individual’s overall health can all influence the likelihood of this side effect occurring. Always consult with a healthcare provider before starting any steroid regimen.


Non-aromatizing steroids like Anavar, Winstrol, Masteron, and Trenbolone have become popular for their ability to promote muscle growth and performance enhancement without the estrogen-related side effects found in other steroids.

However, it’s crucial to remember that these substances still carry potential risks and side effects.

Common side effects can include androgenic effects such as acne and hair loss, cardiovascular issues like cholesterol imbalance, mood changes, and liver damage. More severe risks include potential dependency, long-term health consequences, and legal and ethical implications.

Ultimately, the decision to use non-aromatizing steroids should be made with a comprehensive understanding of the benefits and risks involved.


How do non-aromatizing steroids differ from other steroids?

Non-aromatizing steroids differ from other steroids in that they do not convert into estrogen in the body. This means they typically don’t lead to estrogen-related side effects such as water retention and gynecomastia. Other steroids, known as aromatizing steroids, can convert into estrogen, leading to these potential side effects.

Why might someone choose to use non-aromatizing steroids?

Someone might choose to use non-aromatizing steroids to gain muscle mass and strength without the risk of estrogen-related side effects, such as water retention and gynecomastia (male breast enlargement), which are common with other types of steroids.

What precautions should be taken when using non-aromatizing steroids?

Precautions when using non-aromatizing steroids include:

  • Medical Supervision: Always use these substances under the guidance of a healthcare provider to monitor for potential side effects and adjust dosages as needed.
  • Regular Health Check-ups: Regular blood tests and health check-ups are critical to monitor liver function and cardiovascular health.
  • Dosage: Never exceed the recommended dosage. Higher doses can increase the risk of side effects.
  • Healthy Lifestyle: Maintain a balanced diet, adequate hydration, and regular exercise to support overall health while using these substances.
  • Avoiding Prolonged Use: Long-term use can lead to potential health risks, so cycles should be limited in duration with adequate off periods.
  • Understand the Risks: Be aware of the potential side effects, including androgenic effects such as acne and hair loss, and more serious risks like liver damage and cardiovascular issues.

How does the aromatase enzyme contribute to steroid aromatization?

The aromatase enzyme is responsible for the conversion of androgens, like testosterone, into estrogen. This process is known as steroid aromatization.

When steroids undergo this conversion, it can lead to an increase in estrogen levels in the body, potentially causing side effects such as water retention and gynecomastia. Non-aromatizing steroids do not interact with this enzyme and thus do not convert into estrogen.

+ posts

Hi, I'm Dave Moffat the founder and Chief Editor of steroidsourcetalk.com and certified International Personal Trainer and Certified Nutritionist. My passion has always been bodybuilding but with 15 years' experience in weight loss programs too, it's hard not to mention all that when you're working at your fitness level fullest (I hope). When Im not in the gym or spending time away from my family i often think about what advice would help others achieve theirs goals just like these inspired mine.