In search of a competitive edge, more and more athletes who pump iron are also pumping steroids. "Any body builder who's in national competition and says he's not using anabolic steroids -- he's not being honest with you," says David Bever, associate professor of health education at George Mason University in Fairfax.

"All you have to do is go to any local gym and weight room, and the drugs are there," adds Bever, who recently completed a survey of steroid use among weight-training athletes in the Washington area.

Anabolic steroids, synthetic derivatives of the male hormone testosterone, were developed in the 1930s and introduced in the United States in 1960s. They are approved for prescription-only use as a treatment for such conditions as anemia and osteoporosis, and to help repair tissue in victims of severe burns or other traumatic injuries.

But increasing numbers of healthy athletes -- especially body builders, weight lifters and football players -- take steroids in hopes of gaining weight and strength. Experts warn, however, that the drugs could cause serious side effects, especially with prolonged use.

Athletes obtain steroids from three main sources: "easy" doctors or veterinarians who ignore or bend prescription rules; smuggled purchases from Europe or Mexico, where steroids are readily available; and the flourishing American black market.

Not only are many competitive athletes taking the drugs for unapproved uses, but they are taking them in higher-than-approved doses.

"Athletes don't take therapeutic doses," Bever says. "In America, if a little is good, 16 times more has got to be better."

Bever and a colleague, David Lowry, surveyed 25 amateur athletes who took steroids while training for state or national competition in body building, power lifting and weight training. The survey was based on confidential interviews with the men, who ranged from 19 to 30 years old.

The drugs they reported taking include eight oral steroids and five injectable steroids. The athletes' doses ranged up to 41 times the approved medical dose for the oral steroids and up to 30 times the approved medical dose for the injectable steroids.

Actual dosages of steroids were often even higher, because of the common practice of "stacking," or taking more than one steroid at a time. Athletes typically took both an injectable and an oral form, Bever and Lowry found, and nearly two thirds of them had "stacked" at least three steroids.

Most of the athletes surveyed had been using steroids for more than three years; the longest period of use was seven years. The average weight gain reported during the most recent steroid cycle was more than 20 pounds.

A majority of the athletes took two injectable steroids approved only for veterinary use: boldenone undecylenate (brand name: Equipoise), which is used in training racehorses, and stanozolol (brand name: Winstrol-V), which is used for anabolic therapy in cats, dogs and horses.

The prescribed monthly veterinary dose of Equipoise is 0.5 milligrams per pound of body weight, or 600 milligrams in a 1,200-pound horse. But the survey found two 200-pound weightlifters who were taking up to 1,600 milligrams of Equipoise.

"That's 2 1/2 times what you'd give a 1,200-pound racehorse," says Bever. "These guys were beef on the hoof."

Squibb Corp., which distributes Equipoise, recently discovered a druggawn from studies on patients taking relatively small, doses.

"The scientific data come from reasonable, therapeutic doses," Lamb notes, "but some of these guys are using 200 times the reasonable dose."

The side effects reported in the George Mason survey included increased libido, acne, hair loss, headaches, increased blood pressure, sensitivity of the nipples, puffiness, testicular atrophy and increased aggressive behavior. Of the three athletes who received laboratory tests during their steroid use, two showed abnormal liver function, but both returned to normal when they stopped taking steroids.

In women, the known effects of anabolic steroids include lowering of the voice, growth of facial hair, puffiness, acne and changes in the menstrual cycle.

Many, but not all, of the effects of steroids appear reversible -- they return to normal after the drug is discontinued. The masculinization effect on women taking steroids is not reversible.

The long-term effects are even more worrisome because they are less well known.

"Things usually return to normal a month or so after you stop taking steroids," says Bever. "But the big question is, what happens to someone who has regularly used steroids for 10 or 15 years? There have been no studies."

While few college and high school coaches encourage their athletes to take steroids, Bever says, many take a see-no-evil attitude.

"They certainly don't condone it," Bever says. "They don't want to know about it."

But with or without a coach's blessing, weightlifters and football players who want to get steroids have no trouble finding them in their hometown gyms.

"Kids leave school in June at 250 pounds and come back in September at 280 pounds," Bever says. "You don't gain that kind of weight over the summer eating bananas and bread pudding."

Experts say use of steroids, which used to be confined largely to men in their twenties and thirties, is beginning to spread to women -- and to high school athletes. Use of steroids by young people is especially risky, because it can alter and stunt growth patterns.

A particularly disturbing finding in Bever's survey is that athletes who use steroids over a long period of time find it increasingly difficult to give them up. The longer an athlete's cycle of steroid use, the shorter the break between cycles.

"There is a certain psychological dependence that develops," he says.

The majority of the athletes in his survey reported suffering mild depression for several weeks after discontinuing steroid doses -- which some cited as a reason for increasing the duration of their cycles and shortening the periods between cycles.

Bever, 37, has been a weightlifter himself since age 19.

"Don't think I haven't thought about taking steroids," he says. "But there's that big question.

"We don't really know the long-term effects."