It turns out Melissa McCarthy is just as good in large doses as well. After her fantastic supporting turns in “Bridesmaids” (Oscar-nominated) and “This is 40,” I assumed that I didn’t want too much of a good thing from her profanity-riddled comic tirades.

But when “The Heat” ended after nearly two hours, I was secretly hoping for some outtakes during the credits, something along the lines of that beautifully homicidal aria she delivers in a post-credits “This is 40” outtake that just goes on and on, getting funnier and funnier. After two hours, I still hadn’t had enough. She’s that good.

And I didn’t really see it coming from the trailer for “The Heat,” which looked weak and wobbly. I don’t think trailers play to McCarthy’s strengths; they usually grab the biggest and loudest moments from her performance. In fact, she will take a bit up and down, pushing it farther and longer than you think it can possibly go — it’s the build-up that’s funny as much as the crescendo. (The “little girl balls” bit in her police chief’s office, which could have been a one-liner, but stretches and stretches out, is a prime example.)

“The Heat” doesn’t do a whole lot other than give a nice big canvas for McCarthy to work on, which I suspect is all director Paul Feig (who also did “Bridesmaids”) really wanted. There are some wry send-ups of the buddy cop genre; I liked how Tom Wilson’s police chief, who is usually an angry volcano in these movies, is instead quietly, sadly beaten down after prolonged exposure to McCarthy’s Shannon Mullins. (“My kids call me Grandpa.”)

And attention must be paid to Sandra Bullock, who I didn’t think would quite fit in an improvisation-minded R-rated comedy like this, but throws herself pretty fearlessly into her part. She tightens the screws an extra two or three turns on her tweaked FBI agent until she’s playing a knowing send-up of all those driven career women the movies keep giving us.

But the show is McCarthy’s, and everyone knows it. One of my favorite bits is that throwaway scene at the beginning where she wedges her car in between two squad cars, and she has to wriggle out her car window, into the squad car and out the opposite side. It’s a scene that showcases both her gifts at physical comedy (she’s surprisingly graceful — you try doing that) and verbal, and she unleashes an under-the-breath tirade of colorful profanity that’s a riot. Maybe McCarthy’s approach to comedy will get old, someday. But it feels like she’s just getting warmed up.