L.M.
I had some pretty serious adult acne. Went for about four microdermabrasion treatments (about 10 years ago) and it's never gotten as bad as it once was. (I still have the breakout related to my cycle, but there's not much to do about that outside of medication.)
The procedure was just this side of painful. LIke when your back is itchy and someone scratches it almost to the point of hurting. They are removing layers of bothersome skin to let the new, fresh and unblemished stuff shine. And shine, it does!
Make certain to follow the protocol they give you for cleansing and moisturizing. Truth be told, the package of product cost almost as much as the treatment, but so worth it.
After your skin gets to where you'd like it, you can maintain with a regular at-home ritual and the occasional facial. (I like my facials to be about one-half clinical, one-half relaxing. That's my preference.)