It was the moment every movie star fears most. It happened about two years ago, the actor recalls, a tad defensively. There he stood, in all his A-list glory, in front of the full-length mirror in his bathroom. Nine times out of 10, the mirror was just that big shiny thing he brushed past en route from the shower to the bedroom. He wasn’t one of those actors. Despite his natural charisma, or perhaps because of it, he had always scored low on the Celebrity Vanity Index. “Admittedly, it’s a relative scale,” he says. “We do grade on a curve here.”

His first inclination, as he edged closer to his reflection, was to give himself the benefit of the doubt. He’d been around long enough to appreciate the degree to which harsh lighting and bad angles can make anyone look bad. But now, as the steam dissipated and the reflection took on crystal clarity, the time had come to confront a few essential truths. “You know how actors look in movies that ‘age’ their character over several years?” he asks. “I felt like I was glimpsing myself in the Act Three scene that begins with a tagline that reads, ‘Ten Years Later.’ It was kind of a De Niro in Raging Bull moment. Except not award-winning.”

The skin around his eyes bordered on slack, grayish. Although the rest of his body was in relatively solid shape—he still exercised regularly, albeit with varying degrees of gusto—the star detected telltale indicators of impending decline. There were “little blotchy patches” on his skin and “weird saggy stuff” on his upper torso. The latter was especially disheartening, considering his immediate goals. The actor was circling a film role that would require him to be, in addition to semi-athletic, half naked. Nobody, least of all him, wanted to see this body on a screen 70 feet wide.

Then there was his energy level, which had been heading south for months. Likewise his libido. If being a movie star was all about charisma, and charisma was a kind of energy, then he needed to start exploring alternative energy sources, and fast. To hell with all those damned protein bars and shakes and oxygen chambers. And, frankly, he’d tattoo PATHETIC on his forehead before he’d let some shiny plastics guy cut his face open, or shoot it full of goo, or do any sort of “work.” There’s no sadder specimen, in his view, than the actor who labors under the impression that no one can tell.

The first time he was offered H.G.H.—short for “human growth hormone”—it freaked him out. This was about three years ago, while he was vacationing with friends. During a late-night search for toothpaste, he found his friend injecting a needle into his belly. “Party, drugs, needles, bathroom,” the actor says. “Do the math.”

He was relieved to learn that the syringe contained H.G.H., which the friend was taking as part of doctor-prescribed treatment for a hormone deficiency. “Makes me feel 10 years younger,” the friend said.

The guy did have a certain zip. And he looked, if not younger, pretty good. But still. H.G.H.? The junk all those roided-out ballplayers were using? Why would any actor go there?

As it turned out, though, the actor knew plenty of people who used H.G.H. Most of them sang its praises, saying it made them look and feel stronger, sharper, younger; one of them, a studio executive, told him it had changed his life.

Two weeks later, the star again stood staring into his full-length mirror. He took a deep breath, pinched a layer of belly fat, and plunged the needle in.