Been on the regimen for about 2.5 months with 2 full pumps twice a day. But i guess you can say i've been on it even longer because i was using only 1 pump for once a day for maybe almost a year beore that. I only decided to recently up the dosage and go to twice a day because i had a really bad breakout. As of right now, my skin is very soft and the flaking is very slight only in the morning though. I use 3 pumps of cetaphil ultra hydrating lotion, I have been using this lotion for quite a while now. After switching to 2 pumps a day my skin was definitely very dry and flaky, with slight wrinkling. But after 2.5 months it has definitely subsided with only slight flaking as I mentioned above. I don't know if the same timeline for the flakiness to subside will be the same for others, as I have already been using BP for a year. I also have very oily skin. Also, what helps is to not take such long showers and try to not make the water so hot, it can further dry your skin.
I feel your pain and I only used 1 pump of BP the whole time I was on the Regimen! I had to buy all new make up and face products that was made for dry skin people because all the things I had were aimed towards oily skin. My dryness lasted throughout the whole time I was on the Regimen but my flakiness stopped after two months. I have stopped using the Regimen (I don't believe in being dependent on a product) and my skin is now back to its oily self. I have never been happier to have oily skin LOL It took about 3 weeks for my skin to get back to normal after I stopped using the BP. Hope this helps!