Professional sports leagues could soon face a new federal law clamping down on anabolic steroids and other performance-enhancing drugs used by athletes.

Anabolic steroids are synthetic male sex hormones. They can be prescribed by doctors to treat conditions resulting from low testosterone. Steroid supplements such as DHEA and androstenedione (known as Andro) can be purchased legally without a prescription.

Motivation to abuse these drugs is often driven by the desire to build muscle and improve sports performance, according to the National Institute on Drug Abuse (NIDA).

Congress is considering several proposals to set a single standard on drug testing and penalties for athletes in major professional leagues, including the National Football League, Major League Baseball, and the National Basketball Association. The moves come after widespread criticism this spring from lawmakers over what many saw as professional sport's unwillingness to crack down on steroid abuse among athletes.

Read Web MD's "Lawmakers Upset Over Mixed Signals on Steroids."

Some lawmakers and experts have called for a strict testing and penalty regimen similar to the one used by Olympic authorities. Many blame steroid-using sports professionals for setting a tone that glorifies use by American adolescents. Anabolic steroid abuse is increasing among adolescents, writes the NIDA, most rapidly among girls.

"We've got to cut this off at the head. It doesn't trickle down to our kids, it cascades down," Charles Yesalis, PhD, a steroid researcher from Pennsylvania State University, tells WebMD.

There are many health consequences associated with steroid abuse. In males, decreased sperm count, impotency, and breast enlargement can result from abuse of the drug. In females, the development of male characteristics can occur such as excess body hair and deepening of the voice. Liver abnormalities and cancer, abnormal blood cholesterol levels, and high blood pressure can also be seen when these drugs are abused.

In 2004, 3.4 percent of high school seniors reported in federal surveys having used steroids at some point in their lives, though some other estimates are higher.

But several sports leagues are resisting lawmakers' attempts to regulate drug testing, and it remains unclear how far Congress will go to enact tough standards.

One bill circulating on Capitol Hill would put the federal government in charge of policing drug testing in pro leagues. Athletes would face a two-year suspension for a first offense and a lifetime ban for a second. Leagues would also face still fines for failing to comply with testing rules.

Read Web MD's "Steroid Use: Hitting Closer to Home."

Leagues at Odds

Professional league representatives meeting with federal officials behind closed doors on Capitol Hill Thursday appeared to be far from agreement on whether they would willingly submit to federal oversight.

"For us it's a question of making sure we don't have a situation of one size fits all," Adolpho Birch, labor relations counsel for the NFL, told reporters following the meeting.

Major League Baseball Commissioner Bud Selig in April proposed a system including 50-game suspensions for any players caught using performance-enhancing drugs. Current baseball rules impose a 10-day suspension for a first offense and a 30-day suspension for a second.

The rules don't require public disclosure of players testing positive, a point that remains controversial on Capitol Hill. The Major League Baseball Players' Association has not agreed to the proposal.

Disclosure "is one of they key areas of tension we are facing," says David Marin, a spokesman for Republicans on the House Government Reform Committee, which hosted Thursday's meeting.

Read Web MD's "Why Steroids Are Bad for You."

Bills are 'Dynamic'

Rep. Tom Davis, R-Va., the committee's chairman, told reporters that bills regulating drug testing in sports remain "dynamic" and that he has "an open mind" about how strict the rules will ultimately be.

"We'd like to give the professional sports the opportunity to resolve this themselves, but we'll have some minimum standards. As long as there's pressure to compete, that's what drives this problem," he tells WebMD.

Others warn that self-regulation by pro leagues has already failed.

Yesalis says that drug use -- including steroids and amphetamines -- have a history going back decades in sports including baseball, football, and hockey. He supports proposals turning drug testing over to the United States Anti-Doping Agency (USADA), the group responsible for testing and penalizing Olympic athletes.

"We need to have USADA be the police, judge, jury, and executioner, not the [league] commissioners. And if they let that transparency-in-disclosure deal go, it's been a waste of time," he says.

Read Web MD's "Girls' Steroid Abuse Figures Disputed."

By Todd Zwillich, reviewed by Brunilda Nazario, MD

SOURCES: Charles Yesalis, PhD, professor of health and human development, Penn State University. Adolpho Birch, labor affairs counsel, National Football League. David Marin, majority spokesman, House Government Reform Committee. Rep. Tom Davis (R-Va.). National Institute of Drug Abuse.