How long will the side effects of Retin-A last?

I'm glad to hear that your blemishes are clearing up!Redness, peeling, and skin irritation are all very common side effects with tretinoin, but there are ways to prevent this.  Use only a small, pea-size amount for your entire face, and avoid applying directly to the sensitive skin on your eyelids.  Often times, if you treat through the redness and peeling for 3-4 weeks, it can subside on its own.  That said, tretinoin is available in three strengths, and you are currently using the strongest formulation.  Some times, not all patients can tolerate higher strength tretinoin, and need a milder formulation, or to adjust their dosing frequency to every other day.  If the redness and peeling persist, you may want talk to your dermatologist about adjusting your regimen.