What?? Please explain your statement about cortef only staying in the system 20 minutes. I've read about that the cortef may not work for the whole 8 hours at times in some instances - even for a person who it normally will AND that people metabolize the cortef differently, for some it would never work for the whole 8 hours. Makes sense to try a 6 hour interval. Although might there be some kind of test to determine if a person metabolizes cortef too fast??