How do steroids affect your muscles— and the rest of your body? - Anees Bahji

They’ve caused global scandals. They’re banned

in most athletic competitions. But are steroids actually bad for you? The term “steroids” refers

to a broad category of molecules that share a similar molecular structure, but have many different functions. When people talk about steroids

in the context of sports, they’re referring to a subset of steroids

that resemble testosterone. Though elite athletes and bodybuilders

began using these steroids in the 1950s, today, most steroid users

are actually not competitive athletes, but people seeking

a particular appearance. These steroids have two main effects:

androgenic, or masculinizing, and anabolic, or growth-promoting. These effects mimic naturally-occurring

testosterone, which drives the development

and maintenance of male secondary sex characteristics

and general growth in everyone. That means testosterone

and the synthetic steroids based on it promote body and facial hair growth,

enlargement of the vocal cords and deepening of the voice,

increased muscle mass and strength, and increased stature and bone mass. Recreational steroid users are after

the anabolic, growth promoting effects. To make muscles grow, steroids

first promote protein synthesis— proteins are essential building blocks

of all cells, tissues, and organs, including muscles. Steroids also block cortisol, a signaling molecule that drives

the breakdown of substances including proteins. Finally, they may push the development

of muscle, rather than fat, and boost our metabolism,

shrinking fat deposits. These properties make steroids valuable

for treating many illnesses and injuries. They can help people

with wasting illnesses, like AIDS and certain cancers, maintain muscle mass and help burn victims

recover lost muscle tissue. So if steroids are used as medicine, they must be safe to use recreationally,

right? Well, it’s not that simple. To create the desired muscle growth, recreational steroid users must typically

take doses orders of magnitude higher than those prescribed

for a medical condition. Long term, high dose steroid usage

can have both undesirable and outright harmful effects— some of them dependent

on factors like age, sex, and underlying health conditions. We’re not sure

what all the risk factors are, but we do know recreational steroid use

is particularly risky for adolescents. During puberty, steroid use

can prompt bones to mature before they’re done growing,

causing growth defects. Adolescents are also most at risk for the harmful psychiatric effects

of steroid use. The most common of these, increased

impulsivity and increased aggression, are well-known as “roid rage.” Up to 60% of users

experience these effects. But there are also less common, more damaging psychiatric side effects

like mania and even psychosis. Steroid use can damage organs

including the liver and kidneys, and cause cardiovascular problems

like high blood pressure. While some or all of those effects

may be reversible, steroid use can also cause liver cancer,

especially in males. Though recreational users take steroids

for their anabolic effects, they also experience androgenic effects—

often undesired. That can mean increased body hair,

enlargement of the clitoris, and permanent voice deepening in females. At the same time, excess testosterone-like

steroids can cause feminization in males, because the body converts

the excess into estrogen. This can lead to breast development

and shrinking testicles. These effects are not uncommon— about a third of male steroid users

experience them to some degree. Excess steroid use can also reduce

fertility in males and females— by reducing the sperm in semen or

by causing missed periods and conditions like polycystic ovary syndrome. All these effects may be reversible

if steroid use stops— but they may not be. The specific steroid, the duration of use, and other factors could play

a role in reversibility. Finally, there’s mounting evidence that users are susceptible

to steroid dependence. They can develop tolerance and require

increasingly large doses over time. This increases the risk

of harmful effects, all of which are increasingly common

at higher doses taken for longer durations. Still, there remains little definitive

information on how common and how reversible

almost any of the harms are at different levels of use. We don’t know enough, about

either risk factors or exposure levels, to definitively say any recreational

steroid use will be harm-free.