It is too early to say about co2. but i can say there is lot of problem with co2 factional. i hv done fractional co2 at 24 dec. 2010. now my face is dark and red. it develops pigmention .i forget to apply a cream that was goign to be used before co2 procedure. now i mapplying hydroquoine other cream.In my face lot of scar are there. spe. in right side.