Microdermabrasion. Can be performed as often as every 1 week in certain circumstances. Most patients will find that they settle into a monthly routine, unless they are treating a specific condition like acne (which usually pairs salicylic acid treatments with microderm). The treatment by design only goes a few microns into the epidermis, so it is a gently treatment - despite the sound of it!
Microdermabrasion. If it is a light microdermabrasion, every two weeks is ok, but more aggressive microdermabrasion done by a doctor for acne scarring in which the skin actually becomes raw, should not be done too frequently. Over exfoliation worsens skin's function and causes irritability.
Every 2-4 weeks. Depending on the strength of the microderm, you can have it as early as two weeks but usually we recommend it after one month. Stop Retin-A since it can make you more irritated two days before.
Weekly or monthly. To get the best results, you should have one weekly for a series of 6 followed by monthly maintenance.
Weekly or monthly. Depending on your skin type and what kind of problem you're treating, it's safe to do microderm every 1-2 weeks or once a month. If you have sensitive skin then you probably only want to do it once every month or 2.