Here's something that might help. This is an excerpt from an article by Bill Roberts on Dianabol:
"Dosing of Dianabol is somewhat interesting, in that for most anabolic steroids it is a rather gray area as to what constitutes the maximum useful dose. In the case of Dianabol however, there has long been general agreement that while 50 mg/day is clearly more effective than anything substantially less, more than 50 mg/day adds nothing further, or nothing that can be noticed. This has been my own finding as well.
It is established that 50 mg/day Dianabol taken morning-only causes little HPTA suppression. When used as part of a stack, I recommend divided doses, such as 10 mg five times per day, or 20 mg on arising and 10 mg three times thereafter. The reason for such frequent dosing is that the half life is quite short: about four hours"
In a nutshell, if it's part of a stack, take in divided doses throughout the day. If not, take all at once in the morning.
However, I've read somewhere here that Dbol taken morning only will still cause HPTA supression. I get confused so i just take mine all in one go. Splitting it up throughout the day is a hassle considering my workload.