(Ever take a Z-Pak only to be rewarded with a yeast infection a couple of days later? There you have it.)

Of course, if your illness is minor and you’d prefer some drug-free relief, you’ve got plenty of natural options

take an ACV shot, bust out some yoga poses—but perhaps one of the most effective (and under-the-radar) fixes is propolis, a resin-like compound produced by bees.

You might say propolis is the pocketknife of the wellness world. Not only is it said to have serious immune-boosting powers, but it’s also good for your gut and skin.

Often called “bee glue”—good to know for when you start Googling—it’s the go-to cure-all for many holistic health insiders.

But what, exactly, is it and how does it work? Here, we investigate what all the, um, buzz is about.

What is propolis—and why is it called “bee glue”?

Anything with a nickname like “bee glue” requires some unpacking. Beekeeper’s Naturals founder Carly Stein, who sells propolis in spray form, explains it like this: “People often confuse propolis and honey, but propolis is sticky, hard, and used as the lining of the hive walls,” she says.

Unlike honey, which is sourced from floral nectars, bees source propolis from tree resin and plants.

“It’s basically the immune system of the hive. It’s being used as the ultimate protector,” Stein explains.

One example: When a mouse invades a hive box—something you might not think about, but it happens all the time—the bees sting it and kill it, but obviously can’t drag its body out.

“Bees actually mummify the carcass with propolis and that’s enough to keep the entire environment sterile,” Stein says. It’s a pretty gross visualization—but it does accurately show the strength of the substance.