What Steroids Really Do to Your Body

Credit: Douglas Sacha / Getty Images

Ah steroids, the cause of so many professional athletes’ falls from grace, so many stripped Olympic medals, so many beefcakes at the gym with balloons for biceps. But behind their bad reputation, steroids are actually responsible for some pretty remarkable physical and psychological changes. And that’s what this is about: the chain reaction set into motion when a guy decides he needs that extra edge and starts injecting synthetic testosterone into his body.

“You won’t see the huge results in the gym if you take the same amount of testosterone that your body would make in a day,” says Jay Hoffman, PhD, director of the Institute of Exercise Physiology and Wellness and a professor of sport and exercise science at University of Central Florida. As a result, people take huge doses (anywhere from five to 29 times the normal amount) — and that’s where they start to get into trouble.

“There are correct amounts of hormones that your body needs to live well and prosper — too much and you have problems,” says Linn Goldberg, MD, professor emeritus of health promotion and sports medicine at Oregon Health & Science University. “For example, excess thyroid hormone causes cardiac issues and too much cortisol leads to issues with fat deposition. Having a surplus of testosterone is no different.”

Anabolic steroids, also known as androgens, are a synthetic chemical version of testosterone. You can get the steroids into your body via a shot into muscle (you’ve probably seen the image of someone injecting it into their glutes), but they also come in a pill or cream. “Since they’re illegal, the FDA doesn’t govern what’s in them,” Goldberg says. “So there’s no guarantee that what you buy is actually what the label says it is.” For the sake of this story, let’s say that you get the androgens you want, drop trou, and empty a syringe into your backside. What happens then?

All androgens have two basic effects on your body: They’re masculinizing — they heighten male features — and they’re tissue building, which increases muscle and bone. That said, it’s not enough to inject yourself with the steroid and sit around on your sofa. You still have to put in work at the gym. But do that and within a week or so, you’ll notice that you’re bulking up faster than before. That’s because of the steroid’s ability to boost protein synthesis, the process that builds muscle.

“When you work out, you inflame your muscles and damage them. In a normal situation, cortisone comes in to break them down, so they can get built back up bigger than before,” Hoffman says. “When you have extra testosterone, it antagonizes the cortisone in your body, so the muscles don’t break down as much.” The end result: Faster-healing muscles that can get bigger in a hurry. And because the muscles are healing faster, you don’t need as many rest days. “Each workout is more effective and you can continue pushing your body at a high level,” Hoffman says. That’s why professional baseball players love it so much: Their bodies can stay super strong through the entire grueling 162-game season.

But that’s just the tip of the steroid iceberg. The extra hormones kick off a series of dominos falling throughout your entire body. First, the pituitary gland senses how much testosterone is in your system and stops stimulating the body to produce it on its own. This means the part of your body that makes testosterone goes into hibernation. Unfortunately, that's your testes, which will shrink as a result.

The hormone surge can also change the chemistry in your brain. “Steroids can make people who are predisposed to aggressive behavior even more aggressive,” Hoffman says. “It won’t turn a mild guy into someone who rages at the drop of a hat, but it can make someone who doesn’t have a lot of control over his emotions have even less of a grasp on them.” These manic episodes have a name — ‘roid rage — and they’re something that up to 60 percent of steroid users will experience.

The extra testosterone also brings back issues related to puberty, like acne, while speeding up age-related physical changes, like hair loss. “The steroids stimulate the sebaceous glands, which produce oil, leading to clogged pores and acne,” Goldberg says. “And the hair loss is because testosterone creates a byproduct known as DHT, which can affect hair follicles in men who happen to be prone to male pattern baldness.” And if you haven’t finished growing yet, they can permanently freeze your growth plate (remember: it strengthens bone as well as muscles), stopping your height exactly where you are.

On top of that, some of the extra testosterone breaks down into estrogen, the female sex hormone, as a way for the body to stay somewhat balanced. This can lead to some unwanted physical changes. “In the back of muscle magazines, you’ll see ads for surgeries or supplements to help get rid of breasts in men,” Hoffman says. “That’s because of the steroids. The increased estrogen leads to the formation of what’s called ‘bitch tits’ in the gym.” Doctors have also seen a link between steroid use and bad cholesterol, liver cysts, kidney damage, and blood clots.

With all those negative side effects, why do guys still take them? “A lot of athletes are risk takers,” Goldberg says. “There are risks to playing a sport like football, so this is just something else they do for their sport that has risks.” As for everyone else, it all comes down to hearing what they want to hear. “Sure, a guy starts losing a few hairs and has some acne, but who cares,” Goldberg says. “He was just told he’s an animal at the gym.”