Well, Actually is a weekly column by Slate’s Shannon Palus. Each week, she’ll test health and wellness products to help readers figure out what they should try, what they should skip, and why.
The first time I saw the Foreo Luna in person, I thought it was a vibrator. I was in Miami, had just finished running a marathon, and was dazedly perusing the offerings of the recovery area: a beer tent, gear bag pickup, a table full of brightly colored palm-size electronic silicone disks with little massaging nubs. I stumbled over and clumsily expressed my confusion: “What are you doing here?”
The Luna is meant to be used on your face, a woman at the booth explains. She demonstrates how to apply a cleanser to the nubs and how to move the buzzing device around your face as it exfoliates and removes dirt. It feels nice, especially on my very sweaty skin. I later purchase a mini version to use at home. It costs $100, which is quite a bit of money. But after several weeks of using it, I decide that it’s a nice luxury, worth the price. Though not necessarily because the thing “works.”
The Luna is a “sonic cleansing device,” a descendant of Clarisonic products, which rose to popularity about a decade ago and look like giant electric toothbrushes. (Electric toothbrushes also claim “sonic” technology.) Clarisonics are the primary ancestor in the category of vibrating and oscillating personal hygiene devices. They all claim to offer amazing benefits thanks to their “sonic” technology, a fancy name to match a fancy price tag. Clarisonic claims that its brushes flex the skin to ease dirt out; Foreo says it cleans via “pulsations.” The idea that there’s some novel tech deployed here perhaps helps justify the extensive glowing coverage of the face devices in women’s magazines, and even general-interest and business websites. But all it means is that the devices can vibrate or oscillate extremely quickly.
These brushes seem to benefit from the halo surrounding ultrasonic cleaning, which is a real thing used on small, delicate items like jewelry and dentures. In these devices, objects are submerged in a small vault that vibrates at ultrasonic frequencies. The vibration causes the fluid to drop in pressure, allowing tiny bubbles to form, a phenomenon called cavitation. As these bubbles collapse, they propel gunk off the surface of the fake teeth or shiny objects or what have you. But even if you face-brushed underwater, your vibrating device might not be strong enough to cavitate makeup out of your pores. As a 2004 study on vibrating toothbrushes suggests, the bristles just can’t move fast enough, even though they may indeed be moving at sonic frequencies. So, sonic, when attached to face brushes and toothbrushes, is not advertising that ultrasonic cleaning technology; it just means “it vibrates rapidly.”
I am, at this point in my life, a little bit of a rapid vibrating brush connoisseur. My first came from a drugstore; then, in college, I purchased one from Olay, with a brush head that rotated. Neither its effects nor the feelings it engendered were strong enough for me to form an attachment. This did not stop me from later becoming enthralled by the reports of soft glowing skin from the Clarisonic Mia, so I tried that. The vibrating brush head felt really nice, but I eventually let it go when I realized I just wasn’t motivated enough to replace the brush heads, nor did I have the patience to coax it into alignment with its magnetic charger when it ran low on energy, which seemed like all the time.
My new purchase, the Foreo Luna Mini, is an improvement in that it does not have brush heads that need replacing, the motion feels more interesting and at the same time less aggressive than other brushes, and the charge not only has a regular old port, but it hasn’t run out of juice in the month that I’ve had it. More importantly, I enjoy the time we spend together every night or so in front of my bathroom sink. It’s soothing!
Whether rapidly vibrating anything—cheap bristles or expensive nubs—against your face makes a difference for your skin is sort of unclear. One dermatologist I spoke to, Anand Haryani of Divani Dermatology, said that using a device of any sort should definitely help remove gunk, noting that they’re particularly good for people who have super-oily skin, wear a lot of makeup, or do work somewhere outdoors and dusty. But he also pointed out that people were getting along perfectly fine washing their faces before all these brushes came around. This contradiction tracks with my experience with the Luna: My skin feels very clean and kind of soft after I use it, but it’s not that different from when I really take my time hand-washing my face. The difference is on par with what I feel between a manual and electric toothbrush.
While there is research suggesting that sonic cleansing devices work, it’s sponsored by the companies who make them, as cosmetic chemist Randy Schueller points out on the Beauty Brains. A report from Pacific Bioscience Laboratories, which makes the Clarisonic, for example, argues that its brush reduces the size of pores, based on a group of 30 participants, and even includes an appealing before-and-after photo of a nose. However, that study didn’t include a control group of people who simply washed their face with their hands or a washcloth; perhaps it was the act of regular face cleansing, and the accountability of a study, that helped get some extra pore-enlarging gunk out. The participants also used a face mask during the study, which feels like cheating.
Haryani also says he sees patients that use sonic brushes, some five times a day, under the mistaken impression that more is more or perhaps that acne is a result of dirty skin that can be thwarted with more scrubbing. But overuse of a brush that exfoliates can cause skin to become inflamed and red. People also use the brushes on their bodies, too, which can spread bacteria around. It is important to clean your brush with a little soap, now and then, too, though arguably not as important as it is to clean a microneedling device, which can turn your skin into an actual open wound if used too zealously. Haryani recommends skipping sonic brushes outright if you have eczema. Though, of course, if you follow the instructions, and cut down if your face starts doing something weird, you should be fine.
The reason these brushes enjoy extreme popularity—even the temptation to slip into unhealthily overzealous use—is extremely clear to me. Face devices make you feel like you are really doing something, maybe even something kind of scientific, to care for your skin. When I wash my face with my hands, I just kind of splash water and Cetaphil on it; with the Luna, I feel like I’m buffing a piece of precious machinery, or maybe a piece of artwork, which is a nice way to think about one’s body in this day and age! The device also has a timer, which leads me to spend more time washing my face than I would otherwise. This is the same logic that makes the electric toothbrush I use worthwhile (those also do not confer clear benefits)—it works perhaps simply because I spend more time using it.
What the Luna is really offering is a little face massage. And in this way, the Luna is exactly like the variety of vibrator used for sex: You can make many an argument that a pleasurable activity is beneficial for your appearance and health, but that’s really not the point.
Slate has relationships with various online retailers. If you buy something through our links, Slate may earn an affiliate commission. We update links when possible, but note that deals can expire and all prices are subject to change. All prices were up to date at the time of publication.