WASHINGTON - The commissioner of the Food and Drug Administration told House subcommittees today that Major League Baseball should ban use of the herbal stimulant ephedra, which was linked to the death of a young pitcher at the Baltimore Orioles' spring training camp in February.

Asked if the major leagues should stop their players from using ephedra, used in diet pills and tablets meant to raise energy, Dr. Mark B. McClellan, the F.D.A. commissioner, said, "I think professional sports leagues like baseball teams should take action to protect their players."

McClellan said studies showed that ephedra offers little benefit in improving sports performance and can pose serious health risks. So, for baseball, he said, "there is a medical basis for action on this important issue."

The F.D.A. is considering whether to ban use of ephedra by anyone. But Dr. McClellan said the evidence was clear that the pills are even riskier for competitive athletes, who are already pushing their bodies to the limit, than for other people.

After the pitcher, Steve Bechler, 23, died of heat stroke in Florida, the F.D.A. ordered two dozen companies to stop advertising ephedra as a way to build muscles or enhance athletic performance, saying there was no scientific evidence for those claims. McClellan said then that the F.D.A. was also considering a nationwide ban or sales restrictions on ephedra products, though the scientific evidence on the dangers for people just trying to lose a few pounds seemed less clear-cut.

The companies that make the products have long said they are safe. But just this week, new F.D.A. critiques have been released that cast doubt on the industry's most important safety study, and political momentum seems to be building for a national ban.

McClellan's comments today came after several congressmen lashed out at Eugene Orza, associate general counsel of the Major League Baseball Players Association. Union officials have been reluctant to support banning ephedra despite Bechler's death.

Orza said the major leagues usually outlawed only drugs and substances that were banned by the government. He said the union was waiting to see what the regulators would do before bargaining with baseball owners, who have voiced support for a ban.

But Representative James C. Greenwood, a Pennsylvania Republican who is chairman of one of the two House Energy and Commerce subcommittees that held the hearing, retorted that some of the pill manufacturers had little scientific training and could not even explain what all the ingredients were or how they interacted. He said to Orza, "Instead of protecting this, I don't know why you're not rushing in to ban this to protect your own players."

Orza said the union was also dealing with privacy questions and was hesitant to let the league tell players that "we will come to you at certain times and demand urine." He said the union would agree to drug testing only for cause and not randomly.

A little later, Representative Edward J. Markey, a Democrat from Massachusetts, resumed the attack.

"You don't wait for us to ban the corking of bats," he said. "It seems to me that you're leaving the most important issue, the health of your players, to us."

In his response, Orza said: "Is beer next? Because, in fact, more ballplayers have died from beer."

He added that before Bechler's death, the union was not aware of any serious problems with ephedra among baseball players.

Orza said that after the pitcher died, the union sent a memorandum to players noting that a medical examiner had concluded that ephedra contributed to Bechler's death, though it was probably not the only cause, and warning the players to be "extremely reluctant" to use ephedra products.

Adding to the pressure on the union is that baseball owners have banned the use of ephedra in the minor leagues. The National Football League, Major League Soccer and the National Collegiate Athletic Association have also banned it. The National Basketball Association and the National Hockey League have not.

McClellan said the F.D.A. will decide soon whether to ban ephedra nationwide or restrict its sales. He said it was likely that some of the ephedra companies would appeal the agency's decision in court, setting up an important test of a 1994 law that has made it harder to regulate dietary supplements than drugs.

The F.D.A. has been scrutinizing dozens of deaths, including some of high school athletes, that might be linked to ephedra. Dr. McClellan said scientists were also reviewing more than 17,000 complaints, most relating to health issues, that consumers had made to the government or some ephedra companies over the past decade.

Several lawmakers said that because professional athletes are role models, high school and college athletes might continue to experiment with such stimulants if they were not banned in all the professional leagues.

Stock car racing also came under fire at the hearing. Representative Jan Schakowsky , a Democrat from Illinois, asked why at least one ephedra company had been allowed to sponsor a racing team and promote its products at racetracks.

Mike Helton, president of Nascar, has set limits on how much ephedra was acceptable in tests of drivers. But he also said that the driving teams and tracks were owned by various individuals, and Nascar could not set a blanket policy covering them as well.

By contrast, Adolpho Birch III, the N.F.L.'s counsel for labor relations, said the league began reviewing medical information about ephedra after the first problems with players surfaced in 1999. The N.F.L. banned ephedra use in September 2001.