Anabolic steroids have long been chemicals of choice for bodybuilders wanting to bulk up. But the substances can cause men’s breasts to grow, their hair to fall out and their testicles to shrink. The steroids also show up in blood tests.

Insulin, however, does none of these things, which makes it especially appealing for bodybuilders who want help achieving a desired look.

Doctors and trainers have begun to realize that what began as a small trend among hard-core athletes is spreading to noncompetitive and recreational bodybuilders as well -- a trend that can have potentially deadly consequences.

“It’s filtering down so that the average-Joe bodybuilder has heard about it and is asking serious questions” about whether to take it, says Dr. Nick Evans, an orthopedic surgeon at UCLA-Orthopedic Hospital and a bodybuilder himself.


The practice of non-diabetic athletes injecting themselves with insulin is apparently also being embraced by track-and-fielders and other athletes seeking to build endurance, says Dr. Warren Willey, a physician specializing in family and sports medicine.

The southeastern Idaho doctor became aware of the problem several years ago when he saw a non-diabetic weightlifter pass out outside a restaurant. Willey ran back into the restaurant, grabbed some packets of sugar and poured them into the young man’s mouth. The bodybuilder recovered and acknowledged taking insulin, which he said had helped him gain about 10 pounds and increase muscle fullness.

After writing a firsthand account of the experience in the Physician and Sportsmedicine magazine, Willey has gotten inquiries from patients on how and whether to take insulin and from physicians asking about how patients abuse the hormone.

Up to 10% of bodybuilders may be using insulin, according to a recent report in the British Journal of Sports Medicine. Bodybuilders openly discuss how to use it on muscle-building sites on the Internet, where advertisers also sell insulin and the syringes to inject it, and several cases of comas and fainting have been reported in medical journals.


Roberto Marcelletti, a personal trainer and competitive bodybuilder in Jersey City, N.J., wrote to Ironman magazine to protest the “largest and most shredded competitors” he’d ever competed against in a 2001 bodybuilding competition. “I know GH [growth hormone] and insulin are being used and are undetected by urine samples,” he wrote.

In a recent telephone interview, Marcelletti said he believes that the use of insulin is growing, putting him at a disadvantage in competitions because he never uses it. “It’s being pushed upon amateurs,” Marcelletti said. “It’s manipulating hormones without the knowledge of the stuff. It’ll be Russian roulette -- they don’t know how to do it.”

The insulin is usually taken in conjunction with human growth hormone and sometimes with steroids as well. “These are really dangerous cocktails,” said Dr. Gary Green, an internist and clinical professor in the division of sports medicine at UCLA. “They’re taking awfully big risks.”

Meanwhile, the benefits haven’t been proved. There’s no scientific proof that the insulin does help build muscles or enhance performance.


The bodybuilders take the insulin with a meal, thinking that the body will better absorb and utilize the calories. The steroids and human growth hormone help build new muscle and the insulin is believed by bodybuilders to help prevent it from breaking down. The International Olympic Committee banned insulin use by non-diabetics in 1998.

Insulin is a natural anabolic hormone produced in the pancreas. It helps convert glucose into the energy needed to sustain the body.

Diabetics need additional insulin because their pancreases no longer produce the hormone -- or it fails to respond properly. The resulting surges in blood sugar can cause long-term damage to the eyes, nerves, blood vessels and kidneys.

Injecting unnecessary insulin into non-diabetics can be lethal if the bodybuilder takes too large a dose or takes it at the wrong time. The glucose in the blood drops to dangerously low levels and the person can faint or end up in a coma. The longer-term consequences of using insulin aren’t known, such as whether it might suppress the body’s own insulin production or cause diabetes in the future.


Another danger is that medical emergency personnel might not recognize what has triggered a coma in a person who isn’t diabetic, particularly because many bodybuilders take the insulin secretly.

The problem has been getting more attention lately. In Britain, a 31-year-old man found unconscious at home was taken to a hospital emergency room and given intravenous sugar to save his life. He recovered, and later admitted to using insulin regularly to increase muscle bulk, in addition to taking steroids, the British Journal of Sports Medicine reported. The bodybuilder had been taking insulin three times a week and had been dieting.

Green said there haven’t been any cases reported at UCLA, but the fact that incidents are being reported in medical journals indicates they are just the “tip of the iceberg.”