I always assumed that the Clarisonic cleansing brush was an attempt to clean the skin via sonic cavitation, which is when sound waves cause tiny jets of water to smash into a surface to clean it, like a thousand tiny power hoses (that’s how sonic jewellery/glasses cleaners work). But for sonic cleaning via cavitation to work, you need a hard surface, which glasses and jewellery are, but skin is not, so I was pretty confused.
I recently stumbled upon a paper from 2006 in the Journal of Cosmetic Dermatology, where the inventors of the Clarisonic discuss how it’s designed to work. (Important note: the paper doesn’t present any data of the Clarisonic in action to show that that’s how it actually works, but it’s interesting to see the theoretical background anyway!)
The Clarisonic Brush Head
The Clarisonic brush head has two parts: an outer ring that’s fixed and doesn’t move, and an inner section that’s attached to a motor inside the handle.
From the Clarisonic patents, the inner section rotates back and forth between 8 and 26°, at a frequency of 176 Hz (i.e. it makes 176 cycles from the left to the right and back again in a second; you can also think of it as 352 “sweeps”).
How the Clarisonic Brush Head Works
Here’s the question: if you put the brush against your skin, which part of your skin gets cleaned the most? If you’re a normal sensible person who hasn’t looked at the Clarisonic website in much detail, you’d say, “the part of your skin that’s sitting under the moving inner portion.”
This is where it gets really interesting – the part of the skin that the brush is designed to deeply clean is actually the part with no bristles on it! It’s the skinny ring in between the outer and inner portions (0.05-0.125 inches, or 1.3-3.2 mm according to the patents).
The point of the small rotation of the inner section is so the bristles don’t actually brush over the skin much as it rotates. Instead, the outer and inner sections of the brush move the skin in a gentle twisting movement, so that the section in the ring gets stretched back and forth in a “rapid flexing” motion. Since your skin is more elastic than any unwanted material in your pores, this back and forth movement gradually breaks the adhesion between clogs in your pore and the pore walls, a bit like when you twist an ice cube tray to free the ice cubes. The moving inner bristles then sweep the dirt away as you move the brush over your skin.
To try to visualise the active area, I carefully placed one ply of wet tissue on my Clarisonic Mia 2 and left it to go for a full 1 minute cycle. You can clearly see the ring where the deep cleansing happens. (Don’t fret too much about your skin looking like this afterwards – skin is much more elastic and less fragile than wet tissue!)
The obvious worry here is that the stretching from the brush will cause damage to the skin, but the makers claim that by limiting the angle of rotation and having a back-and-forth oscillating movement rather than a continuous spin like with a rotating brush, the strain is low enough that collagen fibres aren’t damaged. If you’re feeling paranoid, use it on the lowest “speed” – moving up a speed actually increases the angle of rotation, without changing the number of cycles per second.
Unfortunately, I haven’t been able to see a demonstration of whether the Clarisonic actually works on the skin in this way. I think an interesting test would be to cover your skin in some sort of coloured substance that sinks in your pores and hardens slightly, then hold the brush stationary against a section of skin and see if a clean ring forms, but I haven’t been able to think of a suitable material. I’m open to suggestions!
The Clarisonic was provided for editorial consideration, which did not affect my opinion. This post also contains affiliate links – if you decide to click through and support Lab Muffin financially (at no extra cost to you), thank you! For more information, see Disclosure Policy.