New Study Finds Steroid Users May Have Significantly Larger Organs
Anabolic steroid use has long been associated with rapid muscle growth, increased strength, and dramatic physique transformations. That is precisely why millions of people — from competitive bodybuilders to recreational gym-goers — continue to use them despite well-known health risks.
But researchers are increasingly finding that muscles may not be the only tissues growing.
A growing body of evidence suggests anabolic-androgenic steroid (AAS) use is associated with enlargement of several internal organs, including the heart, liver, kidneys, and other tissues. Some imaging studies have reported organ size increases reaching over 40% in certain users, raising concerns that the same anabolic processes driving muscle growth may also be affecting organs that were never meant to grow in that way.
The findings are adding to a broader scientific discussion about the long-term consequences of steroid use — particularly as anabolic steroids become increasingly normalized through social media, fitness culture, and online performance-enhancement communities.
The Muscle Growth Mechanism Does Not Only Affect Muscle
Anabolic steroids work primarily by amplifying the effects of testosterone and related hormones.
They increase:
protein synthesis,
muscle recovery,
nitrogen retention,
and muscle-building capacity.
These effects help explain why steroid users can gain muscle and strength at rates that are often impossible to achieve naturally.
But the body does not have a switch that says "grow muscle only."
Many organs contain androgen receptors, meaning they can respond to elevated androgen levels as well.
Researchers have long suspected that supraphysiological steroid doses may influence:
heart tissue,
liver tissue,
kidneys,
prostate tissue,
and even parts of the brain.
The concern is that growth in these organs is not necessarily beneficial.
Unlike skeletal muscle, organ enlargement can sometimes reflect stress, dysfunction, or pathological remodeling rather than healthy adaptation.
The Study Behind The Headlines
One of the studies drawing attention to this issue used advanced MRI imaging to measure changes in muscle and organ volumes following anabolic steroid exposure.
Researchers found that anabolic interventions increased not only muscle size but also the size of several internal organs. In some measurements, organ growth approached levels that would be considered substantial from a physiological perspective.
Separate testosterone administration trials in healthy men also found dose-dependent increases in liver volume, with larger testosterone exposures producing greater organ enlargement. Researchers specifically warned that some increases in so-called "lean mass" may actually reflect growth in non-muscle tissues, including organs.
This distinction matters because many people assume gains in lean body mass automatically mean gains in muscle.
That is not always true.
Lean mass includes:
muscle,
organs,
connective tissue,
water,
and other non-fat tissues.
An increase in lean mass does not necessarily mean every kilogram came from new muscle fibers.
Why Organ Enlargement Can Be A Problem
When people hear that an organ becomes larger, they often assume larger means stronger.
In biology, that is not always the case.
Sometimes enlargement represents adaptation.
Other times it represents damage.
The heart provides a good example.
Athletes often develop what is known as "athlete's heart," a generally benign adaptation to endurance or strength training. However, steroid-associated cardiac enlargement appears to be different.
Research has linked long-term anabolic steroid use to:
increased left ventricular mass,
impaired heart function,
fibrosis,
reduced ejection fraction,
and elevated cardiovascular disease risk.
A larger heart is not automatically a healthier heart.
In fact, abnormal enlargement can increase the risk of:
arrhythmias,
heart failure,
and sudden cardiac events.
This is one reason cardiologists have become increasingly concerned about long-term steroid exposure.
The Heart May Be The Biggest Concern
Among all organs potentially affected by anabolic steroids, the heart receives the most attention from researchers.
Recent long-term follow-up studies found steroid users had significantly larger left ventricular mass compared with non-users, alongside signs of impaired cardiac function. Some abnormalities persisted years later.
Another major review published in Circulation highlighted growing evidence linking anabolic steroid use to cardiovascular disease, including structural heart changes and increased cardiovascular risk.
These findings are especially concerning because many steroid users are otherwise physically active and often appear outwardly healthy.
Cardiovascular damage can develop silently.
A person may feel strong in the gym while significant changes are occurring internally.
The Liver And Kidneys Are Also Under Pressure
The liver is another organ frequently affected by steroid use.
Researchers have documented:
liver enlargement,
elevated liver enzymes,
hepatotoxicity,
cholestatic jaundice,
and increased risk of liver tumors with certain anabolic steroid compounds.
Oral anabolic steroids appear particularly stressful because they are processed through the liver.
Meanwhile, kidney health has become another growing concern.
Some studies have reported increased kidney volume, structural changes, and signs of renal stress in steroid users.
Although not every user develops severe complications, researchers increasingly view the kidneys as a potentially vulnerable target of long-term anabolic steroid exposure.
The Brain May Not Be Immune Either
One of the most interesting developments in recent years involves the brain.
Researchers using advanced imaging techniques have reported structural and functional differences between long-term steroid users and non-users.
Some studies have linked prolonged anabolic steroid exposure to:
impaired cerebral circulation,
altered brain structure,
cognitive changes,
mood disturbances,
anxiety,
and depression.
This area of research is still developing, but it highlights an important point:
The effects of anabolic steroids extend far beyond muscles.
Why Social Media Complicates The Conversation
The modern fitness industry has created an environment where extreme physiques are more visible than ever.
Platforms like Instagram, TikTok, and YouTube expose users to physiques that would have been rare just a generation ago.
Many people underestimate how common performance-enhancing drug use has become in certain corners of fitness culture.
Researchers have increasingly warned that idealized muscular body standards may contribute to steroid experimentation, particularly among younger men.
The problem is not simply steroid use itself.
It is often the incomplete discussion surrounding it.
Online content frequently highlights:
muscle gain,
fat loss,
strength increases,
and aesthetic improvements,
while spending far less time discussing cardiovascular, hormonal, neurological, and organ-related risks.
Not Every User Experiences The Same Outcomes
An important nuance is that steroid effects vary significantly.
Risk depends on factors such as:
dosage,
duration,
compound selection,
genetics,
age,
pre-existing health conditions,
and use of additional drugs.
A person using moderate doses for a short period may experience very different outcomes compared to someone using high-dose combinations for years.
This variability sometimes creates confusion because users often compare individual experiences.
Someone may point to normal bloodwork after a cycle and conclude steroids are harmless.
Another may experience severe complications.
Scientific research looks at population-level patterns rather than isolated anecdotes.
And the overall trend is becoming increasingly difficult to ignore.
Bigger Is Not Always Better
One of the most misleading assumptions in fitness is that growth is automatically positive.
When it comes to skeletal muscle, growth is usually the goal.
When it comes to internal organs, the picture is very different.
The same biological mechanisms that help build larger muscles may also influence organs that were never intended to be pushed beyond their normal physiological range.
Researchers are increasingly concerned that steroid-induced organ enlargement may represent a warning sign rather than a benefit.
The body can often tolerate significant stress for years before symptoms become obvious.
That delay can create the illusion that everything is fine.
The Bigger Picture
The conversation around anabolic steroids is changing.
The debate is no longer focused only on whether steroids build muscle.
That question was answered decades ago.
The real question is what else they change.
Emerging research suggests anabolic steroids may affect:
the heart,
liver,
kidneys,
blood vessels,
brain,
hormonal systems,
and other organs throughout the body.
Some of these changes may be reversible.
Others may not be.
As more long-term studies become available, researchers are gaining a clearer picture of the physiological trade-offs involved.
The muscle-building effects of anabolic steroids are undeniable.
The growing concern is that muscles may not be the only thing getting bigger.
References
Bhasin S, et al. Effects of Testosterone Administration (and its 5-alpha-reduction) on Parenchymal Organ Volumes in Healthy Young Men. Journal of Andrology.
Wu EX, et al. In vivo MRI quantification of individual muscle and organ volumes for assessment of anabolic steroid growth effects. Steroids. 2008.
Windfeld-Mathiasen J, et al. Cardiovascular Disease in Anabolic Androgenic Steroid Users. Circulation. 2025.
Fyksen TS, et al. Cardiac structure and function in anabolic-androgenic steroid users: a 16-year follow-up study. Open Heart. 2025.
Pahlavani HA, Veisi A. Possible consequences of the abuse of anabolic steroids on different organs of athletes. Archives of Physiology and Biochemistry. 2025.
Tungesvik HM, et al. Imaging cerebral circulation in long-term anabolic-androgenic steroid users and non-using weightlifters. Drug and Alcohol Dependence. 2025.