"It's kind of like if you have a big sweet craving, when you think about it all the time," he says. "I would hang around with teenagers and then things would happen."

The 47-year-old, who asked not to be identified, isn't the typical picture of a sex offender. Thoughtful and articulate, he lives with his wife and together they've made a commitment to work through his sexual deviance. And so far, he's proud to report, they're succeeding. Why? A drug called Lupron gets at least partial credit. The drug decreases testosterone, the hormone that fuels the sex drive. Tom's desire for intercourse is almost nil now -- but along with it has also largely gone the lust for adolescent boys.

"It's a big help," he says. "I would be OK without it because I'm committed to working on this deviant behavior, but it would be a lot harder. It would take a tremendous amount of will power."

Lupron is one of the latest in a series of drugs, called antiandrogens, that trigger a reduction in the production of testosterone. Most commonly used to treat men with prostate cancer -- like New York Mayor Rudolph Giuliani -- and women with endometriosis, it also serves as a "chemical castration" to treat sex offenders.

In late August the new chemical castration drug surfaced in the news during the professional hearings of sex addict and former family practitioner Dr. Joseph Campanella. He had admitted to more than 200 improper sexual liaisons with members of his office staff, hospital employees, patients and homosexual strangers over the past 18 years. His license was finally suspended in January after he was caught masturbating in front of a church bus. When Campanella went before a Chicago medical disciplinary board, he claimed that he had already been "cured" and was ready to return to his medical practice.

His treatment? Six weeks of therapy and Lupron.

Campanella's claims that Lupron can catalyze a quick-fix cure for sexual deviants has raised many questions about the use and efficacy of chemical castration drugs and the very essence of sexual deviance itself. The theory behind Lupron is that reduced sex drive results in a greater ability to control deviant sexual urges, but can flipping a testosterone-laden switch really turn off deviant sexual thoughts? Don't sexual predators and pedophiles prey on vulnerable people and children in part out of a psychological desire to dominate or inflict pain? Can we really transform a person's ethical system though tinkering with their chemistry? Is immorality in the end a treatable physical disability?

Most medical researchers would argue that sex offenders aren't "cured" by such a quick-fix solution. They maintain that Lupron is just one part of a complete and complex treatment regimen. But still some clinicians wax enthusiastic about its ability to transform the dangerous but well-meaning perv into an upstanding citizen.

"It's a wonderful drug," says Dr. Gabrielle Paladino, a psychiatrist who works in a treatment program for convicted sex offenders at California's Atascadero State Hospital. "It's great to see that someone who can't keep their hands off people is able to control those urges."

Other doctors, however, remain skeptical of such ringing endorsements. "There are so many misconceptions about Lupron and other drugs like it," says Dr. Fred Berlin, associate professor and founder of the Johns Hopkins Sexual Disorder Clinic. "Some people respond well to it, others don't. Each sex offender is different."

Lupron differs from Depo-Provera, another common antiandrogen, used primarily as a form of birth control for women. Instead of releasing a form of progesterone into the body as Depo-Provera does, Lupron works directly on the brain. By tripping up the hormone in the brain that signals to the pituitary gland to produce estrogen in women and testosterone in men, it has a generalized desexualizing effect.