Kevin Greene, the Pittsburgh Steelers' 6-foot-3, 249-pound all-pro, no-nonsense linebacker, says he didn't become the National Football League's top quarterback sacker this season merely through rigorous training, clean living and eating three square meals a day.

Greene says he got a boost from a daily regimen of pills, powders and potions that brought increased strength, endurance and recuperative powers. Products with names such as Hot Stuff, The Arousal and The Growling Dog.

"I have found a good mixture of stuff," Greene, a blond, Hulk Hogan lookalike, said with tough-guy confidence. "Fat burners. ... Amino acids three or four times a day. ... Four liver tablets a day. ... High-protein drinks. ... A natural, organic substance before the game to try to get, you know, the juices flowing."

Greene paused and fixed his interviewer with an icy stare. "I suppose you want me to tell you everything I'm using, right?" he said. "Well, I'm not going to do it. For me to be the best, I've got to keep some stuff secret, okay?

"I've got to keep my edge."

In this high-profile, high-stress profession with an average salary of $650,000, the average career lasts only 3.6 years and a mere second in footspeed can mean the difference between keeping a job and losing one. So NFL players are turning increasingly to dietary supplements to try to find an edge.

From Washington to Pittsburgh to San Francisco, players are mixing protein and amino acid powders into their drinks and swallowing tablets that contain stimulants such as ginseng, ephredrine and caffeine before games, according to players, trainers and coaches interviewed in recent weeks. Nutrition and medical experts are divided over whether substances such as the ones a premier quarterback sacker such as Greene takes have anything to do with his ability to charge in and make tackles behind the line of scrimmage.

Some products, used correctly and in moderation, may be harmless, perhaps even beneficial to athletic performance. But other products are marketed with dubious athletic enhancement claims and have not undergone rigorous scientific scrutiny, according to nutrition and consumer health-fraud experts.

"A lot of this stuff is quackery," said Jerry Attaway, strength and conditioning coach of the San Francisco 49ers, who will play the San Diego Chargers in next Sunday's Super Bowl XXIX. "People who use this stuff would be far better off going to a good nutritionist who could teach them how to eat a low-fat, high-carbohydrate diet."

While dietary supplements have been used by athletes since ancient times, their popularity in the NFL has increased since the league began randomly testing athletes for anabolic steroid use in 1990, some coaches and players said. Anabolic steroids -- a synthetic version of the male hormone testosterone -- can increase muscle bulk and strength. NFL players detected using steroids are subject to a minimum four-game suspension without pay.

"So now players are looking for alternatives," Chet Fuhrman, the Steelers' conditioning coordinator, said in his office at Three Rivers Stadium on a recent afternoon.

Motioning toward the team's weight room, Fuhrman added: "We have one player here who was taking 80 to 100 tablets of supplements a day. He cut back this season but he's still taking 40 tablets. Every day."

Fuhrman shook his head in disapproval.

"It's like a ritual for some of these guys. But it's serious business. ... They think: I gotta have it. And, hey, if I don't have it, wow, I'm not gonna go out and make three sacks."

The NFL and organizations such as the International Olympic Committee have banned anabolic steroids because they have potentially harmful side effects, ranging from nausea to liver disease, and they are perceived to give athletes an unfair advantage over their opponents.

Unlike anabolic steroids, which are illegal to use without a prescription and which cannot legally be prescribed to enhance athletic performance, dietary supplements can be purchased at any health food store. These supplements are regulated as foods -- not drugs -- by the Food and Drug Administration.

Boosting a Big Business

Sales in the United States of ergogenic, or performance-enhancing, supplements have been estimated by industry sources at between $100 million and $500 million a year. These products are advertised in muscle magazines and daily newspapers, targeting a range of consumers from competitive bodybuilders to weekend warriors to teenagers who want a better physique.

"Pro athletes are the most gullible; they have the most to lose," said Dan Riley, the Washington Redskins' strength coach. "If they think something's going to make them jump higher, run faster, heal faster, they'll use it."

A Redskins fullback, Frank Wycheck, may be a case in point.

Wycheck was suspended for four games this season after tests showed he had violated the steroids policy. Wycheck said he had unknowingly used steroids when he treated a leg injury last summer with dimethyl sulfoxide (DMSO), an anti-inflammatory solution. "I took the DMSO because I wanted to be 100 percent at training camp," Wycheck said. "I didn't know that the DMSO I'd used was spiked with steroids."

"Frank made a terrible error in judgment, using DMSO," Riley said. "But I've known other players who have used it too."

Riley said he advises players not to treat injuries with DMSO themselves or to take dietary supplements.

"One thing I tell our players is: You'd better get the facts," he said. "And the facts are very definitive: The food we have available is superior in quality to any supplement. If you eat a balanced diet, eat from all the food groups, cut back on fat, cut back on sugar, increase your water intake, there's no need for anyone to supplement."

Supplement manufacturers vigorously disagree. "No one with an average education {about nutrition} could possibly put together a diet as good as the one we can offer. People do not have the smarts to put this together. The average Joe cannot do it," said A. Scott Connelly, founder of MET-Rx. His company markets a nutrient powder mix as "the most perfect food the world has ever seen" and the "secret weapon of the world champion Dallas Cowboys."

The dietary supplement boom has divided NFL strength coaches into two camps: those who recommend these products to players and those who discourage their use, or at least advise athletes to visit their teams' nutritionists.

Whereas the 49ers, Steelers and Redskins strength coaches generally advise against supplement use, their counterparts with the Cowboys and New York Giants make products available in training rooms.

"There's big money in this," the Steelers' Fuhrman said. "A lot of {coaches} will lower themselves to use a certain product and put the name of a winning team behind it. It goes on in the NFL and colleges today."

Mike Woicik, the Cowboys' strength coach, said he is paid personal endorsement fees by two supplement companies -- MET-Rx and Performance Nutrition -- whose products can be found at two locations in the Cowboys' training facility.

"You'd rather not see this," Jay Moyer, the NFL's executive vice president, said of coaches who endorse supplement products, "simply {because of} the perception that he may be doing this as much for his own personal, commercial gain as for his genuine belief that it's a good product."

Moyer added: "If this sort of thing looks like it's going to take hold as a practice, we're going to have to address it."

Woicik said he endorses products that have been proven safe and effective. He said amino acids and protein powders have helped more than half of the Cowboys gain weight, increase strength and recover more rapidly from injuries.

"You know, we're all in the same boat," Woicik said of NFL coaches, "trying to look for something that might help our athletes and that's legal and safe and effective. Especially in the times we're in where the steroid use has really been curtailed because of drug testing."

In addition to steroids, the NFL has banned amphetamines, the widely used "pep pills" of the 1960s and '70s. But other stimulants such as caffeine in high doses and ephredrine, which are banned in Olympic competitions and contained in many supplements, are permitted by the NFL. The IOC has banned many stimulants because they may enhance athletic performance.

Some NFL players seem to believe more stimulants are better than less.

"We've had guys experiment with caffeine {tablets} and ginseng before a game and get sick," Steelers trainer John Norwig said. "Some guys throw up. They have GI {gastric intestinal} distress. They don't need those stimulants." "Some players have been known to drink anywhere from 10 to 15 cups of coffee at a time to get their body going and get them into the frame of mind," Fuhrman said. High-dose caffeine consumption can cause agitation, irritability and dehydration, medical and nutritional researchers have reported.

Attaway, the 49ers' conditioning coach, said some of his players also use ginseng, an herbal stimulant that has been promoted to increase stamina and concentration and decrease fatigue.

"It doesn't do anything to enhance performance," Attaway said, echoing the view of many nutritionists. "But if you like that buzzed feeling. ... that's fine with me. As far as I know, it doesn't hurt you."

While small amounts of ginseng appear to have no negative effects, large doses can cause hypertension, insomnia and depression, some medical researchers have found.

"The problem with some of these products is, athletes don't know how much of it to take," the Cowboys' Woicik said. "I mean, ephredrine for a lot of people is better than caffeine. They develop a tolerance {to caffeine}. So ephredrine for some people is a better solution.

"But when athletes start to think 'Okay, two or three {tablets} is good, I'll take six or seven or eight or 10,' it can become dangerous."

Woicik estimated that between 10 and 12 Cowboys have taken ephredrine before games. Ephredrine is FDA-approved for use as a decongestant and recommended dosages appear on product labels. Some medical researchers have found that excessive use of ephredrine can result in cardiac problems.

"This is not something that we monitor or suggest," Woicik said. "... But some players say it kind of gives them a boost. They feel more alert. They feel more energetic. They feel stronger. ... I don't know how much they take. But I have told them, 'Don't take more than three tablets {of a product containing ephredrine} -- 75 milligrams.' That's the extent of my involvement."

The NFL, in its drug policy, generally advises players that use of medications and supplements "may carry with them a risk of adverse health risks. These substances are sometimes mislabeled or incompletely labeled, and may contain banned or otherwise harmful substances. Thus, players should be cautious in using these unproven substances."

"The whole concept that you can take a bunch of supplements to increase your athletic ability certainly is unproven," said Stephen Barrett, a long-time health-fraud expert and consumer advocate. "The people selling most of this stuff simply have no evidence to back it up."

A Lack of Research

Supplement companies often boast that their products have undergone extensive testing, but rarely, according to Barrett, is their research published in medical or scientific peer-review journals.

Connelly, the MEX-Rx founder, said he hasn't published research on his main product -- the nutrient powder mix -- because its formula is a "closely guarded trade secret."

In a promotional booklet distributed to consumers, Connelly wrote: "The publication of my original work in this area will happen but not until every last patent of my product has been approved. This is not unusual; most companies will not publish original material slated for commercial use until such information is adequately protected."

In an interview last week, Connelly said he has no intention of seeking a patent for his main MET-Rx product and, therefore, no intention of disclosing its "secret formula" in a peer-review journal. "To do that would disclose too much information," he said. Connelly added that he has patented some specific components of the product's formula and he intends to publish research on these components.

"Needless to say, the hundreds of incredibly positive, unsolicited testimonials that we receive each month offer proof that this formula does, indeed, work," Connelly wrote in the promotional booklet.

Supplement takers such as John Gesek, a 6-foot-5, 282-pound Redskins center who formerly played for the Cowboys, don't need to be convinced: they say football players are special people who require special nutrition.

Gesek said three daily servings of MET-Rx enabled him to maintain his weight during a grueling Cowboys' training camp in 1991.

"There was a heat index of 110 down there and my weight actually went up during training camp," he said. "I felt great. A lot of other guys, you'd see them hanging out after practice, waiting for IVs."

Mike Fox, a 6-6, 288-pound Giants' defensive end, said he began using supplements only last year, before his fifth NFL season. "I used to think you didn't ever have to take anything," he said. "But the game puts so much pressure on your body that you actually need some type of supplementation because you couldn't possibly eat all the nourishment that your body needs without getting, you know, pretty heavy."

Fox uses "Ni-The Nourishment," an amino acids powder made by an Australian company called Musashi. Amino acids are the elemental building blocks of protein. Musashi's products are targeted to provide weight loss, weight gain, "instant power," increased muscle mass, mood elevation, "instant energy," muscle recovery from exercise and injury and detoxification from excessive alcohol consumption.

"Your doctors, the FDA, the people who are talking about whether you need supplements or not, they're talking about the average human being who's getting his recommended daily allowances," Fox said. "But that's just a normal situation and a person who has like a regular day. Well, life in the NFL isn't just like a regular day."

Amino Acids Debate

While some medical and scientific researchers have said amino acids can enhance athletic performance -- by releasing growth hormone and, thereby, increasing muscle strength, for example -- others have said they have no value whatsoever and should be avoided.

Two nutritionists, writing in the New York State Journal of Medicine in 1993, warned that high doses and long-term use of amino acid supplements can interfere with normal food consumption and lead to metabolic imbalances. Other researchers have reported that moderate, regulated doses of amino acids have not caused any health problems.

The Steelers' Greene, a 10-year NFL veteran, said his own secret mix of supplements comes from four or five sources, including Musashi.

"I mean, I'm 32 years old," said Greene, who earned almost $2 million this season. "I mean, I'm not getting any bigger. I'm not getting any quicker and faster. I'm just trying to maintain myself through the end of my career."

Greene said he shrugs off suggestions from skeptics that supplements have only a placebo effect. "If you believe it works, I guess it works," he said of the supplements he uses, "regardless of whether you're having a physical or a mental reaction to it or not."

MET-Rx. Brain Power. Super Male. Hot Stuff. The Growling Dog. How does Greene decide which products to use?

"It's a toss-up," he said. "I mean, I'm not educated -- you know, I don't have a degree in vitamin terminology or the scientology of vitamin consumption or whatever. So it's just a best guess, okay?"

Not every NFL player has a Sunday morning date with L-Phenylalanine (a widely marketed amino acid) or Yohimbe bark extract (another stimulant). But rare is the NFL player, trainer or coach who hasn't been solicited to use, if not endorse, such products. "I've been solicited. ... but I guess I'm not very smart because I've always turned them down," said Attaway, the 49ers' coach. "I'd be a hell of a lot better off if I was a prostitute. What's a better thing than having the 49ers behind your product? I know some players who have taken money. They laugh about it. They do it strictly for the money."

Reaching into a trash can in his Three Rivers Stadium office, the Steelers' Fuhrman said, "Here's a letter I just received from a salesman who says he's a lifelong fan of the Steelers who wants our players to benefit from his sports drinks." The salesman promised that his company's drinks "will give you and our Steeler players AN EDGE OVER YOUR COMPETITION."

MET-Rx has signed up six Cowboys players as paid endorsers, including quarterback Troy Aikman and fullback Daryl Johnston. "As a professional player, I look for an edge," Aikman is quoted as saying in a promotional brochure. "MET-Rx gives me the energy, strength and endurance that can make all the difference."

Al Miller, the Giants' strength coach, said he wasn't sold on supplements until 1990, when, as a Denver Broncos' coach, he was introduced to Musashi.

"One product we use is The Growling Dog," Miller said, referring to an amino acids powder. "Game day, we use it a lot. Pre{game} and also at halftime ... I've seen it give players an added tank of energy burst during games ... Musashi's products work ... They're on the cutting edge."

A Musashi executive said he sends the Giants an average of 50 to 60 free bottles of amino acid powders each month and, according to Miller, they're used by more than a dozen players and coaches. While he endorses Musashi, Miller said he hasn't received "one red cent" from the company. "Hopefully, you know, that may come in the future," he said. "... Hey, there ain't nothing wrong with that."

Upshaw Makes a Pitch

Even the executive director of the NFL players' union, Hall of Fame offensive guard Gene Upshaw, has pitched a supplement product to players: a fatty acids capsule that billed itself as a possible alternative to anabolic steroids.

Writing on union letterhead, Upshaw informed players in 1990 that ProForm, manufactured by a company named BioSyn, had enabled him to "run faster, longer and ... be more productive in the weight room.

"I experienced almost immediate results," Upshaw wrote. "... All of this sounds hard to believe, but it happened and is still happening. This product is unbelieveable and you won't believe it until you try it. ..."

A phone call this month to BioSyn found that the company is now known as Eicotec Foods and that ProForm was discontinued in 1991 after limited sales. Barry Sears, the company's founder, said the players' union was paid a "small royalty" for the endorsement.

It's evident from interviews with NFL players, coaches and trainers that some players know little about the products they are using, except that they were recommended by teammates or friends in hometown gyms.

"I'm thinking of getting on a couple of different things this year," Gesek, the Redskins' center, said the other morning. "... There's this stuff -- I can't even think of the name of it right now. It comes in tablet form, and it's been working real well with some friends of mine."

Asked if he knew what substances are contained in the product, Gesek said, "I don't know. But guys say it's really doing a good job on strength, especially late in the season."

While Greene wouldn't discuss his secret "mixture of stuff" in any detail, he said he favors one product before games.

"It's called Up Your Gas," he said with a barely perceptible smile.

Asked if he knew anything about the product's ingredients, the man who terrorized NFL quarterbacks this season with a league-leading 14 sacks shook his head. "I don't know," he said. The smile had vanished. "There's a bunch of words on the back of the bottle. All I know is that it gets me in the mood a little bit more. Nothing big like amphetamines that kind of makes your heart pound out of your chest."

Greene's icy stare was back. "It's just some stuff," he said. "Stuff that helps me keep my edge, okay?"

CAPTION: Amino acids, powders, pills and potions are some of the boosts players are using to try to stay even with competitive pressures and extend athletic careers that often can be cut short.

CAPTION: Says Steelers linebacker Kevin Greene, who led NFL in sacks this season, "I have found a good mixture of stuff ... to try to get, you know, the juices flowing."