I came across a procedure called dermarolling
the other day. As far as I could tell, it seemed to be a treatment for acne scars. I later found recipients of dermarolling reporting that they had suffered from intense pain and bleeding skin. Then I came across people who dermaroll at home. I started out being intrigued and then curious in a repulsed, guilty kind of way (like when you surreptitiously rubber-neck a vehicle crash on the freeway).
A dermaroll, such as the one made by Environ (pictured above), is a small roller covered with hundreds of very tiny needles. The micro-needles penetrate the epidermis. Proponents say that the advantage of dermarolling over chemical peeling is that it doesn't remove the epidermis. Nonetheless, all these little needle pricks will cause bleeding. The skin perceives that it has undergone a trauma, and it starts to produce collagen to repair the wounds.
The at-home users are not entirely masochistic; the domestic versions are reasonably gentle and will cause redness and swelling at most. The experimental at-homers add collagen creams or other topicals which, as a result of all the needle holes, will be absorbed more readily. People report good results with lip lines. Acne scar treatments seem to have more mixed results.
People who undergo the professional version in a salon may indeed be masochists. Or deeply troubled. I found a most distressing (too horrible to inflict on you all) picture of someone having a demaroll treatment. It was not posted online by someone trying to dissuade the public from going anywhere near a dermaroll, but by a dermatologist who performs dermaroll with the Environ Medical Roll-CIT and has a financial interest in the company. It is hard to believe that a picture of a pulpy, bloody face is seen as marketing. This is clearly not a treatment for the squeamish.