"So many people, especially teen-agers, feel self-conscious about their bodies, and if it bothers you that much, you're willing to go to any extreme to change that," says Koegan.
He went to the gym seven days a week, but, as CBS News Correspondent Jane Clayson reports, working out wasn't enough. So he, like millions of other young men in this country, started taking illegal, anabolic steroids.
"People would go, 'Wow, look at you, you're the picture of health,'" he says. "And I'd laugh."
Before long, his blood pressure was through the roof, his hair was falling out and his temper was uncontrollable.
"I was a textbook specimen of 'roid rage," he says. "You wake up pissed off, and the rest of the day you get more and more angry."
The number of young men using steroids has skyrocketed. Last year, nearly half a million teenage boys used steroids.
Dr. Harrison Pope, of Harvard Medical School, has been studying steroid use for 17 years.
"A large number of teen-agers and young adult men who use steroids are taking them purely for personal appearance," says Pope. "These people have no athletic aspirations at all."
Pope gave a computer test to boys as young as 11 years old.
"When they were asked to choose the ideal male body, the average body that they chose is a body that could be attained effectively only with steroids," says Pope.
And when they had added all the muscle the computer would allow, Pope says, some of them asked, "Doesn't it go any higher than that?"
Parents often don't recognize the problem or the dangers.
"If your kid comes through the door and he's got no neck and his traps are out to here, the kid's got a drug problem," Koegan says.
Koegan stopped using steroids three years ago, but the damage may already be done.