Optimal frequency, dosage, and brand of Finasteride for hairloss?

Just had my first hair transplant. My HT surgeon told me that I can take the name brand Finasteride Proscar 3 times a week (Mon Wed Fri). He said to take a quarter of the Proscar tablet on each of the three days which equals to 1.25mg. He also said to make sure to take the name brand Proscar as it is supposed to be more consistent. I'm trying to determine the reasoning as to why he recommends needing only to take 1.25mg 3 times a week. Would it be better to take it every day?