Steroids are banned in sports because they give users a significant physical advantage over clean competitors, pose serious health risks, and undermine the principle of fair play. The World Anti-Doping Agency uses three specific criteria to evaluate whether a substance belongs on its Prohibited List: it enhances performance, it threatens the athlete’s health, or it violates the spirit of sport. A substance only needs to meet two of those three to be banned, and anabolic steroids check all three boxes convincingly.
The Performance Advantage Is Substantial
Anabolic steroids are synthetic versions of testosterone, the hormone that drives muscle growth. When athletes take them in doses far above what the body naturally produces, the results are dramatic. Studies comparing long-term steroid users to drug-free athletes show significantly higher lean body mass, larger individual muscle fibers, and greater capillary density feeding those fibers. In one study published in PLOS One, steroid-using athletes averaged roughly 89.8 kg of lean body mass compared to 74.6 kg in clean athletes. That’s not a subtle edge. It’s the equivalent of carrying around an extra 33 pounds of functional muscle.
These gains are dose-dependent, meaning athletes who take more get more. Lean body mass, muscle fiber size, and strength all scale upward with higher doses. The muscle tissue itself also changes at a cellular level, developing more nuclei per fiber, which helps muscle cells grow larger and repair faster. This creates an advantage that persists even after an athlete stops using, because those extra nuclei stick around for years, potentially giving former users a lasting head start in building strength.
How WADA Classifies Steroids
Anabolic agents sit in the S1 category on the 2025 WADA Prohibited List, right near the top. This category covers anabolic-androgenic steroids along with other anabolic agents and any compounds “with similar chemical structure or biological effects.” That last phrase is intentional. It closes the loophole of designer steroids, where chemists tweak a molecule just enough to dodge a specific ban while preserving its muscle-building properties.
The first official testing for steroids at the Olympics happened at the 1976 Games in Montreal. Many athletes were disqualified and stripped of medals, which pushed the International Olympic Committee to begin making test results public. The regulatory framework has expanded considerably since then, but the core reasoning hasn’t changed: steroids fundamentally distort competition.
Cardiovascular Damage
The heart takes a beating from steroid use, often without the athlete realizing it until significant damage is done. Echocardiographic studies show that supraphysiologic doses cause the heart muscle to thicken abnormally, a condition called myocardial hypertrophy. The chambers of the heart may enlarge, and the heart’s ability to relax between beats becomes impaired. Over time, these changes compromise the heart’s pumping efficiency in ways that don’t always produce obvious symptoms.
Steroids also reshape blood chemistry in dangerous ways. They raise LDL cholesterol (the kind that clogs arteries) while simultaneously lowering HDL cholesterol (the kind that protects them). This combination accelerates coronary artery disease, which is why cardiologists see heart attacks and strokes in steroid-using athletes decades earlier than expected. Blood pressure rises as well, though the increase is typically mild.
Liver Damage and Tumors
Oral steroids are particularly harsh on the liver because they’re chemically modified to survive digestion, which forces the liver to process compounds it wasn’t designed to handle. This leads to four distinct types of liver injury. The mildest is a temporary spike in liver enzymes, which signals that liver cells are being damaged. More concerning is cholestasis, where bile flow from the liver slows or stops, causing jaundice, intense itching, and fatigue.
Long-term use carries more serious risks. A condition called peliosis hepatis can develop, in which blood-filled cysts form throughout the liver tissue. These cysts can rupture and cause life-threatening internal bleeding. The most dangerous outcome is liver tumors, both benign adenomas and hepatocellular carcinoma, a form of liver cancer. These complications are well-documented enough that liver specialists consider them a recognized consequence of prolonged steroid use.
The Body Stops Making Its Own Testosterone
One of the most counterintuitive consequences of taking synthetic testosterone is that your body responds by shutting down its own production. Here’s why: the brain constantly monitors testosterone levels. When it detects an abundance from an outside source, it stops sending the chemical signal (called LH) that tells the testes to produce more. Without that signal, the testes essentially go dormant. Sperm production drops sharply because internal testosterone levels in the testes plummet, even while blood levels remain artificially high.
When an athlete stops using steroids, recovery isn’t guaranteed. The system is supposed to restart on its own, but research has found that more than 20% of men fail to recover normal sperm production after stopping testosterone supplementation. For some, the damage to fertility is permanent. This is one of the health consequences that younger athletes rarely consider when they begin using.
Psychiatric and Behavioral Effects
The psychological toll of steroid use is less visible than the physical damage but no less real. In a study of 56 male steroid users, 71% reported significant aggression they attributed to their steroid use, yet only 9% had experienced aggressive feelings before they started. Forty-five percent reported episodes of actual violence. Depression affected 54% of users, with only 5% reporting depressive feelings before they began using steroids. Anxiety was equally common, reported by 45% of participants.
Perhaps most alarming, 30% of users in that study reported suicidal thoughts or attempts during steroid use. These aren’t minor mood swings. The psychiatric effects can be severe enough to meet formal diagnostic criteria for anxiety disorders (25% of participants) and clinical depression (35%). Three out of four users in the study also reported using other drugs at some point during their lifetime, suggesting that steroid use often exists alongside broader patterns of substance use.
Steroid Users Die Younger
A large study published in JAMA Network Open tracked steroid users over time and compared their death rates to a matched control group. Users were nearly three times more likely to die during the follow-up period, with a hazard ratio of 2.81. The risk of unnatural death (accidents, suicide, overdose) was even higher, at 3.64 times the rate of non-users. Even natural causes of death, primarily cardiovascular events, occurred at 2.24 times the expected rate.
These numbers represent one of the strongest arguments for the ban. Sports organizations have a duty of care to their athletes, and allowing a practice that nearly triples the risk of premature death would be indefensible, regardless of the fairness question.
Why Fair Play Alone Justifies the Ban
Even if steroids were completely safe, they would still threaten the integrity of competition. Sports are built on the idea that outcomes reflect talent, training, and strategy. When one athlete’s muscles are 20% larger because of a pharmaceutical intervention, the competition is no longer measuring what it claims to measure. Clean athletes are forced into an impossible choice: sacrifice their health to keep up, or accept that they’ll lose to competitors who are willing to take that risk.
This is what WADA means by “the spirit of sport,” and it’s the third pillar of its banning criteria. The spirit of sport encompasses ethics, fair play, honesty, health, and respect for rules and other competitors. Steroids corrode all of these values simultaneously, which is why they remain the most prominent category on the Prohibited List and why enforcement efforts continue to expand nearly 50 years after the first Olympic tests.