BOSTON (The Boston Globe) -- Athletes use it for peak performance. Women use it to keep their svelte figures. Teenagers use it as a party pill. Millions of people, knowingly or not, have used ephedrine in dozens of products with familiar names such as Dexatrim Natural, Diet Fuel and Metabolife 356.

For years, critics have charged that ephedrine - an unregulated stimulant marketed as everything from a sex-drive booster to a legal alternative to street drugs - can cause heart problems, seizures and even death. Yet, even as ephedrine racked up 40 percent of all side-effects complaints about dietary supplements to the US Food and Drug Administration, Americans spent $1 billion to $3 billion a year on the drug.

Now, under mounting pressure from advocacy groups who want ephedrine banned, the federal government is turning up the heat on makers of ephedrine products. Over the last month, the FDA has warned six companies to stop selling the synthetic version of ephedrine as a dietary supplement on the Internet, and Health and Human Services Secretary Tommy G. Thompson announced a complete review of the safety of ephedrine.

The federal steps weren't nearly enough to satisfy critics - Public Citizen called Thompson's plan for a study "dangerous cowardice" - and the measures are modest compared to the National Football League's outright ban on ephedrine use. But some observers say the tide may finally be turning against the herbal wonder pill with both the federal review and the certification of a class-action lawsuit in California against one of the ephedrine industry's largest manufacturers, Cytodyne Technologies.

"We want to alert the consumer to the deceptive advertising about the health benefits of these products," said Jim Frantz, a San Diego attorney who has filed the lawsuit on behalf of California residents who have taken Cytodyne's product, Xenadrine. "Ephedrine-caffeine products are harmful to the health of many users."

Makers of ephedrine products say that the safety concerns are overblown, especially compared to the hundreds of thousands of people who have lost weight, gained strength or otherwise attempted to improve their lifestyle with ephedrine.

"Our business is providing supplements that further health and fitness, and the health and safety of our customers is of utmost concern to us," said Bob Chinery, president of Cytodyne. "We believe the case (California lawsuit) is nothing more than an effort to extort a settlement out of Cytodyne."

Indeed, the staying power of Xenadrine and other ephedrine-containing products is the steady stream of testimonials from people who use them. Scientific research shows that ephedrine does promote weight loss, especially for obese individuals.

"It worked for me. I never had a problem," said Barbara Banonis, 54, a registered nurse and health consultant from Charleston, Va. Banonis said she lost 100 pounds in 8 1/2 months the first time she used it and another 40 pounds recently without intentional changes in her diet or lifestyle. "Go with it," she advised others.

But ephedra, also known as ephedrine alkaloid, has been dogged by controversy ever since it went on the market about 15 years ago. Although it is a natural product from a medicinal plant, ephedrine is potent enough to be used as an ingredient in illegal stimulants such as speed or methamphetamines. Some users report that it works because it quickens the pulse like large doses of caffeine, giving the person more energy and suppressing his or her appetite. Some teenagers turn to ephedrine, attracted to its amphetamine-like effects, as a legal alternative to street drugs such as ecstasy.

Ephedrine can be addictive for some people. "I got dependent on it. I couldn't get up, be fully awake without it," said Minnie Lee, 28, a Chicago-area mother. Lee said she uses Hydroxycut but doesn't allow herself to take it every day, fearing too much dependence. "This is my way of cheating until I go to the gym," she said.

Makers of ephedrine already warn minors and those with conditions such as high blood pressure, diabetes, and pregnancy not to use their product, but studies so far have been inconclusive as to whether it is dangerous for healthy adults. For instance, one study found no adverse health effects in overweight yet otherwise healthy people, but eight of 35 subjects originally on ephedrine dropped out because of heart palpitations, elevated blood pressure, or chest pain and thus were not included in the final count of those with adverse effects.

Still, the sheer volume of complaints to the FDA has raised alarms. Since 1994, members of the public and medical professionals have reported almost 1,400 adverse side effects to the FDA, representing more than 40 percent of adverse events for all dietary supplements. In response to mounting complaints, the FDA in 1997 recommended that consumers take no more that 8 milligrams per dose of ephedrine within a six-hour period, and not to use the product for more than seven days. After a congressional inquiry, however, the FDA withdrew the proposal in 2000 because the standards were not supported by scientific evidence.

"There doesn't appear to be a safe dose," said Dr. Christine Haller, a medical toxicologist who has studied the effects of ephedrine at the California Poison Control System and at the Departments of Medicine and Biopharmaceutical Sciences at the University of California at San Francisco. "Even at 8 milligrams, there are problems, especially if taken with caffeine. We need more study."

The current wave of concern about ephedrine began last summer with the deaths of four football players who reportedly used ephedrine, including Minnesota Vikings lineman Korey Stringer, just before the NFL banned players from using it. The National Collegiate Athletic Association and the International Olympic Committee already had banned ephedrine.

One of the players, Rashidi Wheeler, an asthmatic 22-year-old Northwestern football player, collapsed and died during routine preseason drills. His family has sued Northwestern for providing poor medical care, but Northwestern officials say the real culprit is the ephedrine that Wheeler reportedly ingested. Northwestern has countersued the drug manufacturers and distributors of Ultimate Punch, Xenadrine, and GNC, ephedrine-containing strength enhancers that Wheeler may have consumed.

The case is far from clear-cut, however, in part because the medical examiner found that the traces of ephedrine in Wheeler's blood were not enough to be toxic. Wheeler's mother, Linda Will, hired Johnnie Cochran's legal team to sue Northwestern, and they reject the idea that ephedrine played a role in her son's death.

"We stand by the medical examiner's report that ephedra was not the cause of death and hold the university responsible," said James Montgomery, Cochran's Chicago partner.

The California class-action lawsuit against Cytodyne, set to go to trial in October, alleges that the manufacturer falsely claims the health benefits of Xenadrine and does not properly warn consumers of the serious risks associated with its consumption. San Diego attorney Frantz has handled 10 cases against ephedrine manufacturers since 1999 and has 15 cases pending, including against manufacturers of Metabolife and Hydroxycut, in addition to the California class-action lawsuit. His colleague has settled eight cases and has another nine pending.

Because ephedrine can be found in chocolate bars, milk shakes, or simply the pill form, ephedrine is seen as a stealth drug by its critics, meaning that users may not even know what they are swallowing. Also known as Ma Huang or herbal ecstasy, the dietary supplement is sold over the counter, on the streets, and on the Internet for up to $30 for a bottle of 120 pills. The industry reports 3 billion servings sold in 1999.

Because ephedrine is marketed as an all-natural dietary supplement, however, it does not require premarket testing or to maintain quality control before sales to the general public. By contrast, synthetic ephedrine and pseudo-ephedrine, commonly used in cold medications, requires FDA testing and quality control.

Groups such as Public Citizen say, at a minimum, ephedrine should be regulated by the FDA, requiring makers to do health studies and meet FDA quality standards. Ideally, the group would like ephedra banned altogether.

But academic researchers are less convinced that a ban is needed. They say that the side effects reported to the FDA and the misuse of ephedrine as a recreational drug, while worrisome, don't scientifically prove that ephedrine is dangerous to the general public.

"Honestly, I don't know if this is a huge public health issue or a few isolated cases," said Haller of the University of California at San Franciso. "Until we know, we should restrict sales, at least to minors."

Copyright 2002 The Boston Globe. All rights reserved.