A upscale gym patronized by some of the city’s top celebrities proved a weakling in a test of strength with its activist neighbors after the city weighed in on the side of the community.

The Equinox Gym, at 97 Greenwich Ave. in the West Village, was ordered to unwrap its building — a former theater designated an official city landmark — which had been smothered with ads.

A spokeswoman for the gym, whose members include Kiefer Sutherland, Renée Zellweger, Julianne Moore, Bradley Cooper, Mickey Rourke and Jodie Foster, assured neighborhood groups that the building hadn’t been damaged by the multistory billboards.

But the gym’s bottom line took a $65,000 hit — the cost of putting up and taking down the signs.