Do anabolic steroids affect the brain? Research increasingly suggests that they can. Brain imaging studies have found that long-term use of anabolic-androgenic steroids (AAS) is associated with a thinner brain cortex, smaller brain volumes, and brains that appear older than expected for a person’s age. Long-term users have also performed worse on some tests of memory.
These findings come from observational studies, so they show associations rather than proof of cause, and much remains unknown. This article explains what the research has found, how AAS may affect the brain, and what the evidence can and cannot tell us.
How can anabolic steroids reach the brain?
AAS are testosterone and related compounds, and they cross from the blood into the brain. The brain contains androgen receptors, as well as estrogen receptors that respond to estrogen produced from some AAS. These receptors are found in regions involved in emotion, motivation, reward, and memory.
At normal levels, testosterone and estrogen play roles in brain development and function. The concern with non-medical AAS use is exposure to doses far above normal levels, often for long periods, and sometimes in combination with other substances.
Do anabolic steroids change brain structure?
Several imaging studies have found differences between the brains of long-term AAS users and those of weightlifters who have never used AAS.
In one of the largest studies, Norwegian researchers compared magnetic resonance imaging (MRI) scans of long-term AAS users and non-using weightlifters. They found negative correlations between AAS use and brain volume and cortical thickness: AAS users had smaller overall gray matter and cortical volumes and a thinner cerebral cortex (Bjørnebekk et al., 2017).
A follow-up study used machine learning to estimate each participant’s “brain age” from their scans. Long-term AAS users had brains that appeared older than their actual age, compared with non-using weightlifters, and the gap was larger in those with a longer history of use or with dependence on AAS (Bjørnebekk et al., 2021). An older-appearing brain on scans has been associated with poorer cognitive performance and a higher risk of brain disease later in life, although what it means for any individual is uncertain.
Other research has reported differences in the size of the amygdala, a brain region involved in emotion, and in brain chemistry and connections between regions in long-term users (Kaufman et al., 2015).
Can anabolic steroids affect memory and thinking?
Some studies suggest so. A study of long-term AAS users found that they performed worse than non-using weightlifters on a test of visuospatial memory, the ability to remember shapes and patterns, and that poorer performance was associated with greater lifetime AAS exposure (Kanayama et al., 2013).
These differences have not been found on every type of cognitive test, and most studies have been small. Even so, the findings are consistent with the structural differences seen on brain scans.
Do anabolic steroids improve brain function?
There is no good evidence that non-medical AAS use improves memory, focus, or brain health. Users sometimes report feeling more motivated, confident, or energetic during use, but feeling more driven is not the same as improved cognitive function.
Research on testosterone treatment also does not support cognitive benefits. In the Testosterone Trials, a large controlled study of older men with low testosterone, a year of testosterone treatment did not improve memory or other cognitive functions compared with placebo (Resnick et al., 2017). That study used doses intended to restore normal levels, which are far lower than those typical of non-medical use.
Is steroid dependence linked to brain changes?
Yes, according to current research. Studies suggest that around 30% of AAS users may develop dependence, continuing to use despite harmful effects and experiencing withdrawal symptoms when they stop (Pope et al., 2014).
In the brain imaging research, users who met criteria for dependence tended to show more pronounced brain differences, including thinner cortex in frontal regions involved in self-control and emotional regulation (Bjørnebekk et al., 2021). This mirrors findings for other substances, where dependence is associated with similar brain differences, although it is not clear whether the brain differences contribute to dependence, result from it, or both.
What about mood and behavior?
AAS use has been associated with changes in mood and behavior, including irritability and, in some individuals, aggression, although the evidence on aggression is mixed. After use stops, the drop in hormone levels can be accompanied by low mood, fatigue, and reduced sex drive while natural testosterone production recovers. Our article on testosterone recovery after steroids explains why this recovery can take months or longer.
Persistent low mood after stopping AAS can be serious. Anyone experiencing ongoing depression or thoughts of self-harm should seek medical help promptly rather than waiting for hormones to recover.
Can steroids affect blood flow to the brain?
AAS use is associated with raised blood pressure, unfavorable cholesterol changes, and an increased tendency for blood to clot, all of which are risk factors for stroke. Strokes in young AAS users have been described in case reports. Our article on steroids and heart health explains these cardiovascular effects in more detail.
Are the brain changes reversible?
This is not yet known. Most brain imaging studies have compared users and non-users at a single point in time, so they cannot show whether differences develop gradually, whether they reverse after use stops, or whether some differences were present before use began. Longer-term studies following users over time are ongoing.
Limitations of the evidence
The research on AAS and the brain has several important limitations. Most studies are observational and relatively small, and they rely on users’ own reports of which compounds they used and for how long. AAS users may also differ from non-users in other ways that affect the brain, such as use of other substances, sleep, or mental health history.
For these reasons, the findings should be understood as consistent warning signs rather than precise measures of risk for any individual user.
The bottom line
Do anabolic steroids affect the brain? The evidence suggests that long-term use can. Brain imaging studies have linked long-term AAS use to thinner cortex, smaller brain volumes, and brains that appear older than expected, particularly in heavy and dependent users. Long-term users have also performed worse on some memory tests.
There is no good evidence that AAS improve brain function. Because the research is observational, it cannot prove cause and effect or show whether changes reverse after stopping. Our guide to the key facts about steroids covers their wider effects on the body. Anyone concerned about memory, mood, or thinking after AAS use should speak with a qualified healthcare professional.
References
Bjørnebekk A, Walhovd KB, Jørstad ML, Due-Tønnessen P, Hullstein IR, Fjell AM. Structural brain imaging of long-term anabolic-androgenic steroid users and nonusing weightlifters. Biological Psychiatry. 2017;82(4):294–302.
Bjørnebekk A, Kaufmann T, Hauger LE, Klonteig S, Hullstein IR, Westlye LT. Long-term anabolic-androgenic steroid use is associated with deviant brain aging. Biological Psychiatry: Cognitive Neuroscience and Neuroimaging. 2021;6(5):579–589.
Kanayama G, Kean J, Hudson JI, Pope HG Jr. Cognitive deficits in long-term anabolic-androgenic steroid users. Drug and Alcohol Dependence. 2013;130(1–3):208–214.
Kaufman MJ, Janes AC, Hudson JI, et al. Brain and cognition abnormalities in long-term anabolic-androgenic steroid users. Drug and Alcohol Dependence. 2015;152:47–56.
Pope HG Jr, Wood RI, Rogol A, Nyberg F, Bowers L, Bhasin S. Adverse health consequences of performance-enhancing drugs: an Endocrine Society scientific statement. Endocrine Reviews. 2014;35(3):341–375. Resnick SM, Matsumoto AM, Stephens-Shields AJ, et al. Testosterone treatment and cognitive function in older men with low testosterone and age-associated memory impairment. JAMA. 2017;317(7):717–727.
