It’s shear madness! Brooklyn’s hipster beard craze has grown so popular that men in New York are rushing to doctors for “facial hair transplants” — surgery that helps make beards look thicker and less patchy, sources said.

Stubble-challenged guys are forking over up to $8,500 for the beard-boosting procedure, which has spiked in popularity in recent months, plastic surgeons told The Post.

“Brooklyn is probably the nucleus of the trend, it’s the hipster ‘look’ guys want. If you have a spotty beard, and you let it grow out, it looks sloppy, ” said Dr. Jeffrey Epstein, a Midtown-based plastic surgeon.

“[Clients] want full beards because it’s a masculine look. Beards are an important male identifier,” he added.

Epstein performs two or three beard implants per week — up from just a handful each year a couple years ago, he said.

The specific hipster-inspired style — a lumberjack-meets-roadie hybrid — was made popular in neighborhoods such as Williamsburg, Bushwick and Park Slope, doctors and patients said.

One happy patient is Danny, 27, whose beard used to be so patchy, he was forced to “fill it in” with an eyebrow pencil, he said.

Two years ago, he paid $8,500 for the surgery, which he considers a fashion statement.

“I have a baby face but now I’m able to look older. My fashion statement is a little edgy, and I do like the ‘rugged look,’” he said,

He added, “It’s one of the best investments I’ve ever made.”

During the procedure, doctors remove hair from other body parts, including the head and chest, before implanting it in the face.

New beards grow back normally and can be shaved.

The hair-raising trend is also popular with female-to-male transgenders, Hasidic Jews, and guys who simply aren’t very hairy, doctors said.

“It’s the style. It’s just more common now to see scruff than 10 years ago,” said Dr. Yael Halaas, a Midtown plastic surgeon who performs the procedure.

“We’ve been getting a lot more calls about it,” she said.

A 39-year-old New Yorker, who works in the catering industry, got a beard transplant to make him feel younger, DNAinfo.com reported.

“I had contemplated [getting a beard transplant] for approximately eight months,” he said. “Knowing the results, I wish I hadn’t wasted so much time deciding.”