I dunno but Sky honest to God I think the CR sucks cause it does NOT work on me at all but the regular does....the CR I stay awake all night and have to take a real Ambein then to get some sleep...I also feel odd on it...I think the stuff is crap..The way it works they say is the 10 mgs hit you as normal and later the 2.5 mgs kick in but thats not true in my case