cDonalds' McRib and its cult-like following are back. Thank goodness the "disconcerting" sandwich is only returning for a limited time only, says Meredith Melnick at TIME. Because if you knew about all the unpronounceable ingredients packed into the McRib, you might think twice about wolfing down the sauce-drenched pork concoction. Think you can stomach what's inside? Read on:

How many ingredients are there?
At face value, the sandwich contains just pork, onions, and pickle slices slathered in barbecue sauce and laid out on a bun. But the truth is, there are roughly 70 ingredients. The bun alone contains 34, says TIME's Melnick. In addition to chemicals like ammonium sulfate and polysorbate 80, the most egregious may be azodicarbonamide — "a flour-bleaching agent most commonly used in the manufactur[ing] of foamed plastics like gym mats and the soles of shoes." According to McDonald's own ingredient list, the bun also includes calcium sulfate and ethoxylated mono- and diglycerides, among other chemicals.

Ooof. What's the meat made of?
Pig innards and plenty of salt. Typically, "restructured meat product" includes pig bits like tripe, heart, and scalded stomach, says Whet Moser at Chicago Magazine, citing a 1995 article by Robert Mandigo, a professor at the University of Nebraska. These parts are cooked and blended with salt and water to extract salt-soluble proteins, which act as a "glue" that helps bind the reshaped meat together.

Is it really that bad for you?
Well, it's certainly not good for you. Though "slightly trimmer than the Big Mac," which contains 540 calories and 29 grams of fat, says Christina Rexrode at USA Today, the McRib, first introduced in 1982, still packs in 500 calories and 26 grams of fat. And despite its name, one thing you won't find inside a McRib is bones. The absence of any detectable "rib" is what gives the unnutritious mush its "quirky sense of humor," says Marta Fearon, McDonald's U.S. marketing director.

Sources: Chicago Magazine, McDonald's, TIME, USA Today