Pure pressure!

On any given Saturday night, nightlife impresarios and twins Derek and Daniel Koch can be found rubbing elbows with models and moguls at their Meatpacking District hot spot Toy.

But when the clock struck midnight on New Year’s Eve, the 30-year-old brothers of downtown after-dark fame traded in their bottle of bubbly for a toast with Voss water.

It’s a tradition the twins began six years ago after a half-decade of partying and indulging. “It takes a toll — physically and mentally,” says Derek of the pitfalls that lurk behind the velvet rope.

And so the siblings typically dry out from Jan. 1 to their birthday on March 25 — for a much-needed break from their late-night, booze-soaked profession.

Christian Johnston

Cheers to the new year! Celebrity stylist Lauren Rae Levy and p.r. honcho Drew Hunter are among New York’s young elite who “competitively cleanse.”

“It’s like 85 days of sobriety,” says Daniel, who recently had to break it to his new girlfriend that he’d be embarking on a dry spell of nearly three months. “But who’s counting?”

These creatures of the night are among a growing number of self-flagellating New Yorkers who treat — then beat — themselves post-holidays by temporarily giving up vices such as alcohol and sweets, sometimes replacing them with liquid diets (blue-green algae juice and garlic-oregano shots, among them).

According to Denise Mari, owner of Organic Avenue, the uber-popular NYC-based juicing mecca, business has doubled year over year since 2006, with an explosion in volume in 2012. And there’s always a spike in sales this time of year with those desperate to cleanse away their sins.

“People tend to go extreme — they need to be kicked in the ass,” says Danielle Pashko, a longtime NYC nutritionist who guides high-rollers from Citibank, J.P. Morgan and Merrill Lynch.

“It’s kind of like a bipolar attitude — splurging with mayhem and nonstop debauchery for weeks, and then total self-deprivation.”

The hard-charging industries that power NYC — fashion, finance and nightlife among them — are at the forefront of the New Year detox and pilgrimage to purity.

“These people are highly successful, competitive and stressed out. They’re cosmopolitan and social and mostly men,” says Pashko.

Drew Hunter, the 29-year-old founder of One PR, and his pal, celebrity stylist Lauren Rae Levy, recently embarked on an Organic Avenue juice cleanse together.

“With my crazy lifestyle, if I don’t cleanse, I’ll just feel sluggish,” says Hunter, who estimates spending more than $6,000 in pricey juice programs over the past five years — especially after back-to-back parties during Fashion Week, his busiest time of the year.

“Everyone does it in our business — it’s crazy,” says Hunter, who started his second-ever New Year cleanse yesterday — and converted his entire office of six people to the practice.