AS HIS 40s turned into his 50s, Lucas Green started noticing a difference when he looked in the mirror, and it wasn't crow's-feet or bags under his eyes. "My hair had changed," he says. "It was lifeless and much thinner. My dad was mostly bald at 60, and I could see myself on the road to that."

Green wasn't finding hair on his pillow or in the shower in the mornings, but he knew he was definitely losing his hair. And if you're familiar with the numbers on male hair loss, you know he was hardly alone: According to the American Hair Loss Association, roughly 65 percent of all men will experience some form of hair loss by age 35, and by age 50 that number spikes to 85 percent.

So he was in the majority -- but this wasn't a club Green was eager to join. "I had always had good hair," he says. "And now I could see myself losing it. To be honest, I saw it as the inevitable outcome. I was becoming resigned to it."

Green turned his resignation into resolve after a conversation with Kelly Morrell, a friend who runs Scalp Confidential, a hair-restoration clinic in London. He had assumed the only hair-loss remedies were drugs or transplants, and he wasn't interested in either. "I asked a few questions," he recalls. "And Kelly explained that there were other viable treatments available."

Morrell recommended a third option: Calecim Advanced Hair System, a topical serum that nourishes weak follicles with proteins essential to hair growth. Derived from stem-cell technology, Calecim contains PTT-6, a proprietary ingredient that reduces scalp inflammation and contains exosomes and growth factors that have been shown to increase hair-follicle cell production by 24 percent in the brand's lab testing.

Intrigued by the possibilities -- and the topical application -- Green signed on. He did have some mild anxiety about the process (the first step involves using a professional-grade micro-needling tool to "stamp" the scalp before applying the serum), and so took the option to have this done at the clinic instead of at home. But apart from some minor discomfort -- "and nothing more," Green says -- the Calecim treatment was a snap. More important, it didn't involve drugs or surgery, and it's ideal for people in the earlier stages of hair loss -- so it was the best choice for him.

Before long, he had tangible validation of his decision. "I could see definite changes in about six weeks," Green says. The thinning process he'd been noticing was now reversing, and there was an unexpected bonus, too: "I was quite surprised that as the treatment went along, my hair appeared younger than before." That was a result of the regrown hair being thicker and denser than Green's previously thinning hair, imparting an overall darker look.

The typical Calecim treatment is a six-week program of twice-weekly applications, followed by a maintenance phase of once-a-week treatment for three months. You can administer the treatment at home by yourself, or you can have it done by a professional at a clinic or salon, like Green. It's possible to see a difference in hair growth in six weeks, as Green did, but results may vary, and the sooner you start the treatment after seeing signs of thinning, the better your chances of positive results.

Additionally, since Calecim's proprietary active ingredient is naturally derived, there are absolutely no side effects associated with the treatment -- unless you count compliments from colleagues, friends, and loved ones. Green says he had no problem handling all the positive feedback, noting that most of it came "from those who didn't see me so frequently, since the changes were gradual." Those folks, he adds, "were full of praise" for his new look.

Today, Green couldn't be happier. After his first six-week treatment, he shifted to monthly visits for three to four months. Now he plans to return to Morrell's clinic for some maintenance every three to six months to keep his hair looking thick and healthy. And as he approaches the age that proved telling for his dad, Green is happy -- in this one respect, anyway -- not to be following in his father's footsteps.