Busta Rhymes used some muscle against a New York gym employee Wednesday and was busted for it!

And by muscle, we mean Muscle Milk protein drink -- even though Busta was working on his guns, it wasn't brute force he used against at Steel Gym employee who asked the rapper to have his camera crew leave ... Busta (nee Trevor Tahiem Smith, Jr.), 43, was arguing with a gym employee about having his workout recorded, when the exchange got physical and Smith threw a cardboard container of strawberry Lean Body Protein and hit the dude in the face.

"Things got heated. Busta splashed water on him and the employee threw water back. Busta’s security got between them. The cops came and (the employee) kept changing his story." eyewitness Sean Aird tells the New York Daily News. Rhymes commented, upon his release early Thursday morning, "It's stupid." His attorney says, "It's ridiculous; it was literally a bottle of Muscle Milk."

Busta later Instagramed a message to his fans: "Thanks to everyone who helped expedite this evening for me," he wrote on Instagram. I'm good and we're back to the grind. Heading 2 the studio 2 turn the bulls--- into GREATNESS. I'm super good."