Mintz was famous largely because his Cenegenics Medical Institute based in Summerlin promoted the use of steroids and human growth hormone as an anti-aging therapy for some patients, and he showcased his own bodybuilder physique as evidence of the benefits of the regimens he espoused.

Mintz died Sunday from bleeding during a biopsy, Yocheved said. Mintz had been suffering from problems with his brain, possibly because of a stroke, she said.

She said many of his patients were flying in from all over the world for his service today at 10 a.m. at King David Memorial Chapel, 2697 Eldorado Lane, near Eastern Avenue.

"So many people are better because for having known him," she said.

Mintz's company, founded in 1998, grew to include offices in Charleston, S.C.; Boca Raton, Fla.; Tokyo; Hong Kong and Seoul, South Korea, and claimed to have more than 12,000 patients.

But many doctors warned that while human growth hormone had beneficial effects on body composition, there were safety concerns about long-term use.

Mintz and some of his patients said the Cenegenics Medical Institute treatments gave them more energy, better sex lives and improved physical conditions.

Mintz told "60 Minutes" last year he had been taking human growth hormone for about 10 years. He also said he wasn't certain if the treatments could be detrimental in the long run.

"No, I'm not absolutely sure," he said. "Only a fool is absolutely sure. Am I confident? Do I sleep well at night? Yes."

Mintz had rippling muscles when the Review-Journal interviewed him January 2006. Although he recommended hormone therapy for about 30 to 35 of his patients, most of his work was in promoting exercise and healthy lifestyles, he said. He also said about 1,000 of his patients were physicians.

Yocheved said her husband became interested with the field in 1990, when he became fascinated at his 70-year-old mother's ability to run marathons.

Yocheved recalled that her husband had wondered, " 'Why is it that a time when her contemporaries are dying off... she can still go?' "

At the time, he had recently retired after building up a successful radiology company. He decided to come out of retirement to help people, she said.

"He was so passionate about what he was doing," she said.

Mintz's efforts were covered by GQ Magazine, CNBC and NBC's "20/20," among others.

In addition to his wife, Mintz is survived by their four sons, Dr. Ari Mintz, Steven Mintz, Jeffery Mintz and Jonathon Mintz.