It depends, even when you mention medium as a depth. My erbium laser is by Scition (www.sciton.com for more information that might help), and allows three different ways to apply erbium energy. A micropeel means you treat all the skin about 20-60 microns deep. Takes 2-5 days for the skin to heal, redness then disperses usually within another week. Erbium can also be fractionated, called profractional xc. That treats 11% or more of the skin with vertical microchannels that are deeper than the microlaser. We average about 300 microns with most patients. That will also take about 4 days to heal, redness another 4. But we are still able to provide that in a clinic setting and minimal anesthesia (ie topical). Conventional erbium laser may be what was described to you. Now we treat 100% of the skin surface again, but are back to the 250-500 micron depth. That takes about 7 days to heal, but the redness persists for another 1-6 weeks. It also requires at least IV anesthesia. More aggressive treatments take longer to heal. But they offer more results. Microlaser and profractional treatments are best designed for more than one treatment, while the erbium is just once.