After she’s convicted of insider trading, Michelle Darnell (Melissa McCarthy) tries to rebrand herself as America’s sweetheart with her reluctant friend Claire (Kristen Bell) at her side. (  / Universal)

After exploding into the public consciousness in the 2011 hit “Bridesmaids,” Melissa McCarthy became known for a particular brand of slapstick, raunchy comedy, cultivating a crude, coarse, socially inept persona that grew less appealing with every iteration.

Last year’s “Spy” proved a delightful exception: Finally, McCarthy could prove what a nimble, likable actress she is, and the film bubbled and squeaked with low-key, feminist optimism. With “The Boss,” McCarthy has sadly reverted to form, playing yet another selfish, cluelessly narcissistic character given to pratfalls and prodigious profanity streaks. Here she plays Michelle Darnell, the “47th richest woman in America,” who resembles a cross between Suze Orman, Martha Stewart and McCarthy’s reliably unpleasant alter ego. After a promising opening number — set at one of Darnell’s self-improvement rock shows — this sludgily paced vehicle kicks into its natural gear, lurching from one set piece to the next with workmanlike, if frequently clumsy, efficiency.

The plot is predictably schematic: After doing time at a Club Fed-like state prison for insider trading, Michelle seeks to re­invent herself, enlisting her long-suffering assistant Claire (Kristen Bell) to help get her back on her feet. When she accompanies Claire’s daughter to a club meeting and hears how much money there is in cookie sales, the light bulb goes on. Michelle dragoons her team into developing a similar group in which profit-sharing will take the place of badges and in which unsavory talk about sexuality and a hair-pulling, tush-kicking, bloodletting street rumble are by no means out of the question.

(Hopper Stone/Universal Pictures)

Impeccably coiffed and cosmeticized, and dressed in a series of inexplicably burkalike turtlenecks, McCarthy projects undeniable zing in “The Boss,” which was directed and co-written by her husband, Ben Falcone. Bell does her best to remain respectfully bland as Michelle’s sweet-natured, patient foil, while Peter Dinklage seems to be channeling his lamest Derek Zoolander as an oily competitor with whom Michelle shares some dubious personal history.

In fact, credit for the most notable performance in “The Boss” should probably go to newcomer Eva Peterson, a somber-faced, leggy beauty who delivers a commanding, deadliest-of-deadpan performance as one of Michelle’s new young proteges. She’s a standout in what is otherwise a thinly constructed excuse to watch McCarthy engage in her signature lowbrow physical gags (an errant fold-out couch, a slip down some stairs, a ­sushi-induced stroke) and breathtakingly blue dialogue — here given extra shock by usually being uttered in the company of angelic tween girls.

Presumably, “The Boss” will give McCarthy’s core audience exactly what they expect from a woman who in five short years has become her own cheerful, aggressively distasteful brand. Although her charisma is still undeniable, there’s also no denying that McCarthy is capable of much more than she’s allowing herself to do here. There comes a point when every force of nature starts to look just plain forced.

R. At area theaters. Contains sexual content, brief drug use and profanity. 99 minutes.