From fancy lasers to injectables, dermatologists have no shortage of beauty tools in their offices (none of which should ever be used by an untrained hand, BTW). But when board-certified dermatologist Mona Gohara, MD gets home for the night, there’s one at-home device in particular that she can’t live without—and that you should be swearing by, too.

In the latest episode of Dear Derm, Dr. Gohara calls out the microneedling device as her favorite at-home tool on the market. Her fandom comes thanks to the prickly roller’s effective, triple-whammy of skin-boosting benefits. Microneedling devices are teeny, tiny needles— don’t worry, they don’t hurt—that create microscopic puncture wounds in your skin, which kicks collagen production into gear, increases product absorption, and gets your blood pumping. The result of the whole process is a radiant complexion that products on their own just can’t compete with. Though they may sound fancy—and you certainly can drop a few hundred dollars on a top of the line one—you can grab a microneedler on Amazon for under $20, and it will do the job just fine.

As for the tool that she’d ditch ASAP? While she sings the praises of gua sha to lift and sculpt the face and loves a bit of microcurrent here and there to de-puff and get the lymphatic drainage going, we were stunned to find out that Dr. Gohara could live without one of most common tools around. Wonder which one she’s talking about? Click the vid above, and school yourself on the beauty tools out there that can help your products work better, which means happier, better-functioning skin.

Want more Mona? Check out her go-to skin-care routine. And the one thing she wants you to remember when you’re dealing with acne.