Friday nights in the fall mean high school football. But that wholesome slice of Americana also contains a dark undercurrent–a marked rise in the use of human growth hormone by high school aged students.

In a recent survey of 3,705 kids, 11 percent of teens in grades 9 through 12 reported having used synthetic human growth hormone without a prescription. That means that at any high school football game, it's likely that at least two players on the field will have tried human growth hormone.

And it's not just athletes who reported having used HGH. The survey, carried out by the Partnership for Drug-Free Kids and funded by a grant from the MetLife Foundation, found no statistically significant difference in the athletic involvement between synthetic HGH users and non-users.

Sports doping scandals have been dominated by steroids for many years, and the study confirmed a gradual, long-term increase in teens' reported lifetime use of steroids. Steroid use among teens has increased from 5 percent in 2009 to 7 percent in 2013. But the latest percentage of reported HGH use is more than double the previous year.

Even though he called the numbers "alarming," the news didn't surprise Travis Tygart, the CEO of the US Anti-Doping Agency, the organization charged with managing the anti-doping program for all Olympic sports in the United States.

"The pressures to win at every level of our sports today are incredible," Tygart said. "And you can see young kids in high school, who maybe have a hope and a prayer for a financial scholarship to go to college or maybe just so their parents can brag at the office, the pressures that are put on them to win by any means necessary. It's ripe for them to use these drugs in order to gain an advantage."

Synthetic HGH has been available since 1985 and is prescribed to treat growth disorders in children, hormone growth deficiency in adults and muscle-wasting disease associated with HIV/AIDS. Without a prescription, it can be used to pack on muscle.

That's where younger athletes may take cues from their professional heroes. Major League Baseball was the first of the major U.S. sports leagues to introduce in-season testing for HGH, but other sports have been slower to react. In September, the National Football League came to an agreement with its players union on a drug policy that includes HGH testing, but the negotiations took three years.

"Kids in our country idolize the players, and the lack of leadership and no testing for HGH in the NFL has been hurtful to the fight for clean athletes' rights and the integrity of the sport," Tygart said. "It is ridiculous that it has taken this long for the HGH test to be put into place, and while it is a good first step, the proof will really come from how it is put into practice.”

Even for non-athletes, the spike in the reported use of HGH can be tied to societal pressure. A study in the January issue of JAMA Pediatrics found that nearly 18 percent of adolescent boys were highly concerned about their weight and physique. And boys were as likely to feel pressure to gain weight and muscle as to lose weight.

Young women aren't immune to HGH's marketing efforts as a way to obtain a perfect body, according to the Partnership for Drug-Free Kids survey. The difference between the proportions of teen boys and teen girls who reported using synthetic HGH (12 percent vs. 9 percent) was not statistically significant.

Prescription HGH is expensive, with daily injections at a cost between $125 and $250 a week. Even non-prescription HGH runs a few hundred dollars for a month's supply, and even then, buyers can't be sure what they're getting. Supplements and powders that claim to include HGH are easy to find online and in fitness stores, but those are regulated by the Federal Trade Commission, rather than the Food and Drug Administration, with a different level of scrutiny applied.

"People believe that if it's on the shelf it must be OK," said Steve Pasierb, president and CEO of the Partnership for Drug-Free Kids. "But these are only ever taken off the market if they're proven harmful. Whereas a drug or food product has to first be proven effective before it goes on the market. The public doesn't understand that nuance. It's an important one, but they don't understand it."

There were some rays of hope in the study. Only 8 percent of teens agreed that using performance-enhancing substances in sports was OK "if it's the only way to win," and this percentage has continuously declined over the past five years.

Pasierb said that could be an opening for parents to talk with their kids about the risks of HGH. His group's research shows that kids who live in households where parents reinforce the health dangers of drugs tend to use in lower levels than their peers who don't hear that at home.

"Parents think they have no power," Pasierb said. "But in the end, disappointing your parents is one of the key reasons kids don't use. It's higher than whether it's illegal or anything like that. I often say to folks, 'Your kids want to push you to the wall but they don't want to push you that next step. They don't want to lose your love and respect. They'll make you nuts, but they don't want to lose you.'"