I know this is confusing because you'll see it both ways depending on who you consult.  Renova works well either way but I counsel my patients to wash, apply moisturizer, wait 5-10 minutes (brush your teeth, etc)  and THEN do the Renova because it pretty much eliminates the problem of irritation.  Irritation (redness andor flaking) is the main reason people stop using it.  Renova provides the cosmetic effects we all love but it also helps to prevent skin cancers and normalize sun damaged skin cells.  Dr. I