Would you mind posting a picture of how your lips look when they are peeling/cracked/red? It would be interesting to see what your condition looks like. I think for many of us it takes many days for the lips to build up skin which will become noticable after a certain amount of time. Your case sounds quite different, it sounds like your lips are "only" cracked and can heal quite quickly after taking EPO and also go back to their cracked stage quite quicky after stopping to take EPO.