Why is Retin A supposed to be applied to the skin 30 minutes after the face has been washed?

You ask a good question as to why we do the things we do. And in this case, the only reason why we recommend that patients wait until the face is no longer wet or damp to apply the medication is to reduce the possibility of irritation. When your skin is wet or dry, the medications penetrate easier and deeper into the skin. Since RetinA is not a product that works in a matter of days, its more weeks or months--getting it to penetrate deeper or easier increases the chance of irritation more than the chance of clearance. So, then how long do we recommend to people? Well, everyone dries at a different rate. Did you pat dry? Did you air dry? Do you live in a humid environment? So, most pick a time that is easy and convenient to remember. 30 min. Can you wait 40 min or 1 hour? Sure. You will get the exact same effect. Can you go shorter? Well, probably. It all depends on your skin and can you be consistent. Some people don't wait even 5 minutes are have no issues with irritation. Is it wrong? No. Not if there is no irritation. It will work all the same in the long run. So, if you want to try a little less time due to convenience--I would say it is ok to try as long as there is no problems with redness, peeling or tightness.